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 __FBSDID("$FreeBSD: stable/12/stand/libsa/ufsread.c 324556 2017-10-12 14:57:05Z imp $");
48
49 #include <ufs/ufs/dinode.h>
50 #include <ufs/ufs/dir.h>
51 #include <ufs/ffs/fs.h>
52
53 #ifdef UFS_SMALL_CGBASE
54 /* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
55 (see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
56 support both UFS1 and UFS2. */
57 #undef cgbase
58 #define cgbase(fs, c) ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
59 #endif
60
61 typedef uint32_t ufs_ino_t;
62
63 /*
64 * We use 4k `virtual' blocks for filesystem data, whatever the actual
65 * filesystem block size. FFS blocks are always a multiple of 4k.
66 */
67 #define VBLKSHIFT 12
68 #define VBLKSIZE (1 << VBLKSHIFT)
69 #define VBLKMASK (VBLKSIZE - 1)
70 #define DBPERVBLK (VBLKSIZE / DEV_BSIZE)
71 #define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
72 #define IPERVBLK(fs) (INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
73 #define INO_TO_VBA(fs, ipervblk, x) \
74 (fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
75 (((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
76 #define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
77 #define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
78 ((off) / VBLKSIZE) * DBPERVBLK)
79 #define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)
80
81 /* Buffers that must not span a 64k boundary. */
82 struct dmadat {
83 char blkbuf[VBLKSIZE]; /* filesystem blocks */
84 char indbuf[VBLKSIZE]; /* indir blocks */
85 char sbbuf[SBLOCKSIZE]; /* superblock */
86 char secbuf[DEV_BSIZE]; /* for MBR/disklabel */
87 };
88 static struct dmadat *dmadat;
89
90 static ufs_ino_t lookup(const char *);
91 static ssize_t fsread(ufs_ino_t, void *, size_t);
92
93 static uint8_t ls, dsk_meta;
94 static uint32_t fs_off;
95
96 static __inline uint8_t
fsfind(const char * name,ufs_ino_t * ino)97 fsfind(const char *name, ufs_ino_t * ino)
98 {
99 static char buf[DEV_BSIZE];
100 static struct direct d;
101 char *s;
102 ssize_t n;
103
104 fs_off = 0;
105 while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
106 for (s = buf; s < buf + DEV_BSIZE;) {
107 memcpy(&d, s, sizeof(struct direct));
108 if (ls)
109 printf("%s ", d.d_name);
110 else if (!strcmp(name, d.d_name)) {
111 *ino = d.d_ino;
112 return d.d_type;
113 }
114 s += d.d_reclen;
115 }
116 if (n != -1 && ls)
117 printf("\n");
118 return 0;
119 }
120
121 static ufs_ino_t
lookup(const char * path)122 lookup(const char *path)
123 {
124 static char name[UFS_MAXNAMLEN + 1];
125 const char *s;
126 ufs_ino_t ino;
127 ssize_t n;
128 uint8_t dt;
129
130 ino = UFS_ROOTINO;
131 dt = DT_DIR;
132 for (;;) {
133 if (*path == '/')
134 path++;
135 if (!*path)
136 break;
137 for (s = path; *s && *s != '/'; s++);
138 if ((n = s - path) > UFS_MAXNAMLEN)
139 return 0;
140 ls = *path == '?' && n == 1 && !*s;
141 memcpy(name, path, n);
142 name[n] = 0;
143 if (dt != DT_DIR) {
144 printf("%s: not a directory.\n", name);
145 return (0);
146 }
147 if ((dt = fsfind(name, &ino)) <= 0)
148 break;
149 path = s;
150 }
151 return dt == DT_REG ? ino : 0;
152 }
153
154 /*
155 * Possible superblock locations ordered from most to least likely.
156 */
157 static int sblock_try[] = SBLOCKSEARCH;
158
159 #if defined(UFS2_ONLY)
160 #define DIP(field) dp2.field
161 #elif defined(UFS1_ONLY)
162 #define DIP(field) dp1.field
163 #else
164 #define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
165 #endif
166
167 static ssize_t
fsread_size(ufs_ino_t inode,void * buf,size_t nbyte,size_t * fsizep)168 fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
169 {
170 #ifndef UFS2_ONLY
171 static struct ufs1_dinode dp1;
172 ufs1_daddr_t addr1;
173 #endif
174 #ifndef UFS1_ONLY
175 static struct ufs2_dinode dp2;
176 #endif
177 static struct fs fs;
178 static ufs_ino_t inomap;
179 char *blkbuf;
180 void *indbuf;
181 char *s;
182 size_t n, nb, size, off, vboff;
183 ufs_lbn_t lbn;
184 ufs2_daddr_t addr2, vbaddr;
185 static ufs2_daddr_t blkmap, indmap;
186 u_int u;
187
188 /* Basic parameter validation. */
189 if ((buf == NULL && nbyte != 0) || dmadat == NULL)
190 return (-1);
191
192 blkbuf = dmadat->blkbuf;
193 indbuf = dmadat->indbuf;
194
195 /*
196 * Force probe if inode is zero to ensure we have a valid fs, otherwise
197 * when probing multiple paritions, reads from subsequent parititions
198 * will incorrectly succeed.
199 */
200 if (!dsk_meta || inode == 0) {
201 inomap = 0;
202 dsk_meta = 0;
203 for (n = 0; sblock_try[n] != -1; n++) {
204 if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
205 SBLOCKSIZE / DEV_BSIZE))
206 return -1;
207 memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
208 if ((
209 #if defined(UFS1_ONLY)
210 fs.fs_magic == FS_UFS1_MAGIC
211 #elif defined(UFS2_ONLY)
212 (fs.fs_magic == FS_UFS2_MAGIC &&
213 fs.fs_sblockloc == sblock_try[n])
214 #else
215 fs.fs_magic == FS_UFS1_MAGIC ||
216 (fs.fs_magic == FS_UFS2_MAGIC &&
217 fs.fs_sblockloc == sblock_try[n])
218 #endif
219 ) &&
220 fs.fs_bsize <= MAXBSIZE &&
221 fs.fs_bsize >= (int32_t)sizeof(struct fs))
222 break;
223 }
224 if (sblock_try[n] == -1) {
225 return -1;
226 }
227 dsk_meta++;
228 } else
229 memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
230 if (!inode)
231 return 0;
232 if (inomap != inode) {
233 n = IPERVBLK(&fs);
234 if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
235 return -1;
236 n = INO_TO_VBO(n, inode);
237 #if defined(UFS1_ONLY)
238 memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
239 sizeof(dp1));
240 #elif defined(UFS2_ONLY)
241 memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
242 sizeof(dp2));
243 #else
244 if (fs.fs_magic == FS_UFS1_MAGIC)
245 memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
246 sizeof(dp1));
247 else
248 memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
249 sizeof(dp2));
250 #endif
251 inomap = inode;
252 fs_off = 0;
253 blkmap = indmap = 0;
254 }
255 s = buf;
256 size = DIP(di_size);
257 n = size - fs_off;
258 if (nbyte > n)
259 nbyte = n;
260 nb = nbyte;
261 while (nb) {
262 lbn = lblkno(&fs, fs_off);
263 off = blkoff(&fs, fs_off);
264 if (lbn < UFS_NDADDR) {
265 addr2 = DIP(di_db[lbn]);
266 } else if (lbn < UFS_NDADDR + NINDIR(&fs)) {
267 n = INDIRPERVBLK(&fs);
268 addr2 = DIP(di_ib[0]);
269 u = (u_int)(lbn - UFS_NDADDR) / n * DBPERVBLK;
270 vbaddr = fsbtodb(&fs, addr2) + u;
271 if (indmap != vbaddr) {
272 if (dskread(indbuf, vbaddr, DBPERVBLK))
273 return -1;
274 indmap = vbaddr;
275 }
276 n = (lbn - UFS_NDADDR) & (n - 1);
277 #if defined(UFS1_ONLY)
278 memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
279 sizeof(ufs1_daddr_t));
280 addr2 = addr1;
281 #elif defined(UFS2_ONLY)
282 memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
283 sizeof(ufs2_daddr_t));
284 #else
285 if (fs.fs_magic == FS_UFS1_MAGIC) {
286 memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
287 sizeof(ufs1_daddr_t));
288 addr2 = addr1;
289 } else
290 memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
291 sizeof(ufs2_daddr_t));
292 #endif
293 } else
294 return -1;
295 vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
296 vboff = off & VBLKMASK;
297 n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
298 if (n > VBLKSIZE)
299 n = VBLKSIZE;
300 if (blkmap != vbaddr) {
301 if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
302 return -1;
303 blkmap = vbaddr;
304 }
305 n -= vboff;
306 if (n > nb)
307 n = nb;
308 memcpy(s, blkbuf + vboff, n);
309 s += n;
310 fs_off += n;
311 nb -= n;
312 }
313
314 if (fsizep != NULL)
315 *fsizep = size;
316
317 return nbyte;
318 }
319
320 static ssize_t
fsread(ufs_ino_t inode,void * buf,size_t nbyte)321 fsread(ufs_ino_t inode, void *buf, size_t nbyte)
322 {
323
324 return fsread_size(inode, buf, nbyte, NULL);
325 }
326
327