1 /* $OpenBSD: udf_subr.c,v 1.27 2024/04/13 23:44:11 jsg Exp $ */
2
3 /*
4 * Copyright (c) 2006, Miodrag Vallat
5 * Copyright (c) 2006, Pedro Martelletto
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/buf.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/mutex.h>
35 #include <sys/stat.h>
36 #include <sys/mount.h>
37 #include <sys/vnode.h>
38 #include <sys/lock.h>
39 #include <sys/dirent.h>
40 #include <sys/disklabel.h>
41
42 #include <crypto/siphash.h>
43
44 #include <isofs/udf/ecma167-udf.h>
45 #include <isofs/udf/udf.h>
46 #include <isofs/udf/udf_extern.h>
47
48 int udf_vat_read(struct umount *, uint32_t *);
49
50 /*
51 * Convert a CS0 dstring to a 16-bit Unicode string.
52 * Returns the length of the Unicode string, in unicode characters (not
53 * bytes!), or -1 if an error arises.
54 * Note that the transname destination buffer is expected to be large
55 * enough to hold the result, and will not be terminated in any way.
56 */
57 int
udf_rawnametounicode(u_int len,char * cs0string,unicode_t * transname)58 udf_rawnametounicode(u_int len, char *cs0string, unicode_t *transname)
59 {
60 unicode_t *origname = transname;
61
62 if (len-- == 0)
63 return (-1);
64
65 switch (*cs0string++) {
66 case 8: /* bytes string */
67 while (len-- != 0)
68 *transname++ = (unicode_t)*cs0string++;
69 break;
70 case 16: /* 16 bit unicode string */
71 if (len & 1)
72 return (-1);
73 len >>= 1;
74 while (len-- != 0) {
75 unicode_t tmpchar;
76
77 tmpchar = (unicode_t)*cs0string++;
78 tmpchar = (tmpchar << 8) | (unicode_t)*cs0string++;
79 *transname++ = tmpchar;
80 }
81 break;
82 default:
83 return (-1);
84 }
85
86 return (transname - origname);
87 }
88
89 /*
90 * Do a lazy probe on the underlying media to check if it's a UDF volume, in
91 * which case we fake a disk label for it.
92 */
93 int
udf_disklabelspoof(dev_t dev,void (* strat)(struct buf *),struct disklabel * lp)94 udf_disklabelspoof(dev_t dev, void (*strat)(struct buf *),
95 struct disklabel *lp)
96 {
97 char vid[32];
98 int i, bsize = 2048, error = EINVAL;
99 uint32_t sector = 256, mvds_start, mvds_end;
100 struct buf *bp;
101 struct anchor_vdp avdp;
102 struct pri_vol_desc *pvd;
103
104 /*
105 * Get a buffer to work with.
106 */
107 bp = geteblk(bsize);
108 bp->b_dev = dev;
109
110 /*
111 * Look for an Anchor Volume Descriptor at sector 256.
112 */
113 bp->b_blkno = sector * btodb(bsize);
114 bp->b_bcount = bsize;
115 CLR(bp->b_flags, B_READ | B_WRITE | B_DONE);
116 SET(bp->b_flags, B_BUSY | B_READ | B_RAW);
117 bp->b_resid = bp->b_blkno / lp->d_secpercyl;
118
119 (*strat)(bp);
120 if (biowait(bp))
121 goto out;
122
123 if (udf_checktag((struct desc_tag *)bp->b_data, TAGID_ANCHOR))
124 goto out;
125
126 bcopy(bp->b_data, &avdp, sizeof(avdp));
127 mvds_start = letoh32(avdp.main_vds_ex.loc);
128 mvds_end = mvds_start + (letoh32(avdp.main_vds_ex.len) - 1) / bsize;
129
130 /*
131 * Then try to find a reference to a Primary Volume Descriptor.
132 */
133 for (sector = mvds_start; sector < mvds_end; sector++) {
134 bp->b_blkno = sector * btodb(bsize);
135 bp->b_bcount = bsize;
136 CLR(bp->b_flags, B_READ | B_WRITE | B_DONE);
137 SET(bp->b_flags, B_BUSY | B_READ | B_RAW);
138 bp->b_resid = bp->b_blkno / lp->d_secpercyl;
139
140 (*strat)(bp);
141 if (biowait(bp))
142 goto out;
143
144 pvd = (struct pri_vol_desc *)bp->b_data;
145 if (!udf_checktag(&pvd->tag, TAGID_PRI_VOL))
146 break;
147 }
148
149 /*
150 * If we couldn't find a reference, bail out.
151 */
152 if (sector == mvds_end)
153 goto out;
154
155 /*
156 * Okay, it's a UDF volume. Spoof a disk label for it.
157 */
158 if (udf_transname(pvd->vol_id, vid, sizeof(pvd->vol_id) - 1, NULL))
159 strlcpy(lp->d_typename, vid, sizeof(lp->d_typename));
160
161 for (i = 0; i < MAXPARTITIONS; i++) {
162 DL_SETPSIZE(&lp->d_partitions[i], 0);
163 DL_SETPOFFSET(&lp->d_partitions[i], 0);
164 }
165
166 /*
167 * Fake two partitions, 'a' and 'c'.
168 */
169 DL_SETPSIZE(&lp->d_partitions[0], DL_GETDSIZE(lp));
170 lp->d_partitions[0].p_fstype = FS_UDF;
171 DL_SETPSIZE(&lp->d_partitions[RAW_PART], DL_GETDSIZE(lp));
172 lp->d_partitions[RAW_PART].p_fstype = FS_UDF;
173 lp->d_npartitions = MAXPARTITIONS;
174 lp->d_version = 1;
175
176 lp->d_magic = DISKMAGIC;
177 lp->d_magic2 = DISKMAGIC;
178 lp->d_checksum = dkcksum(lp);
179
180 error = 0;
181 out:
182 bp->b_flags |= B_INVAL;
183 brelse(bp);
184
185 return (error);
186 }
187
188 /* Get a vnode for the Virtual Allocation Table (VAT) */
189 int
udf_vat_get(struct umount * ump,uint32_t lb)190 udf_vat_get(struct umount *ump, uint32_t lb)
191 {
192 struct vnode *vp;
193 struct unode *up;
194 int error;
195
196 error = udf_vget(ump->um_mountp, lb - ump->um_start - 3, &vp);
197 if (error)
198 return (error);
199
200 up = VTOU(vp);
201 up->u_vatlen = (letoh64(up->u_fentry->inf_len) - 36) >> 2;
202
203 ump->um_vat = malloc(sizeof(struct unode), M_UDFMOUNT, M_WAITOK);
204 *ump->um_vat = *up;
205
206 ump->um_flags &= ~UDF_MNT_FIND_VAT;
207 ump->um_flags |= UDF_MNT_USES_VAT;
208
209 vput(vp);
210
211 return (0);
212 }
213
214 /* Look up a sector in the VAT */
215 int
udf_vat_map(struct umount * ump,uint32_t * sector)216 udf_vat_map(struct umount *ump, uint32_t *sector)
217 {
218 /* If there's no VAT, then it's easy */
219 if (!(ump->um_flags & UDF_MNT_USES_VAT)) {
220 *sector += ump->um_start;
221 return (0);
222 }
223
224 /* Sanity check the given sector */
225 if (*sector >= ump->um_vat->u_vatlen)
226 return (EINVAL);
227
228 return (udf_vat_read(ump, sector));
229 }
230
231 /* Read from the VAT */
232 int
udf_vat_read(struct umount * ump,uint32_t * sector)233 udf_vat_read(struct umount *ump, uint32_t *sector)
234 {
235 struct buf *bp;
236 uint8_t *data;
237 int error, size;
238
239 size = 4;
240
241 /*
242 * Note that we rely on the buffer cache to keep frequently accessed
243 * buffers around to avoid reading them from the disk all the time.
244 */
245 error = udf_readatoffset(ump->um_vat, &size, *sector << 2, &bp, &data);
246 if (error) {
247 if (bp != NULL)
248 brelse(bp);
249
250 return (error);
251 }
252
253 /* Make sure we read at least a whole entry */
254 if (size < 4) {
255 if (bp != NULL)
256 brelse(bp);
257
258 return (EINVAL);
259 }
260
261 /* Map the sector */
262 *sector = letoh32(*(uint32_t *)data) + ump->um_start;
263
264 brelse(bp);
265
266 return (0);
267 }
268