usr/src/boot/sys/boot/common/ufsread.c

   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         size_t n;
 183
 184         blkbuf = dmadat->blkbuf;
 185
 186         if (!inode)
 187                 return (0);
 188         if (inomap != inode) {
 189                 n = IPERVBLK(&fs);
 190                 if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
 191                         return (-1);
 192                 n = INO_TO_VBO(n, inode);
 193 #if defined(UFS1_ONLY)
 194                 memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
 195                     sizeof(struct ufs1_dinode));
 196 #elif defined(UFS2_ONLY)
 197                 memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
 198                     sizeof(struct ufs2_dinode));
 199 #else
 200                 if (fs.fs_magic == FS_UFS1_MAGIC)
 201                         memcpy(&dp1, (struct ufs1_dinode *)blkbuf + n,
 202                             sizeof(struct ufs1_dinode));
 203                 else
 204                         memcpy(&dp2, (struct ufs2_dinode *)blkbuf + n,
 205                             sizeof(struct ufs2_dinode));
 206 #endif
 207                 inomap = inode;
 208                 fs_off = 0;
 209                 blkmap = indmap = 0;
 210         }
 211         return (IFTODT(DIP(di_mode)));
 212 }
 213
 214 static ssize_t
 215 fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
 216 {
 217         char *blkbuf;
 218         void *indbuf;
 219         char *s;
 220         size_t n, nb, size, off, vboff;
 221         ufs_lbn_t lbn;
 222         ufs2_daddr_t addr2, vbaddr;
 223         u_int u;
 224
 225         /* Basic parameter validation. */
 226         if ((buf == NULL && nbyte != 0) || dmadat == NULL)
 227                 return (-1);
 228
 229         blkbuf = dmadat->blkbuf;
 230         indbuf = dmadat->indbuf;
 231
 232         /*
 233          * Force probe if inode is zero to ensure we have a valid fs, otherwise
 234          * when probing multiple paritions, reads from subsequent parititions
 235          * will incorrectly succeed.
 236          */
 237         if (!dsk_meta || inode == 0) {
 238                 inomap = 0;
 239                 dsk_meta = 0;
 240                 for (n = 0; sblock_try[n] != -1; n++) {
 241                         if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
 242                             SBLOCKSIZE / DEV_BSIZE))
 243                                 return -1;
 244                         memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
 245                         if ((
 246 #if defined(UFS1_ONLY)
 247                             fs.fs_magic == FS_UFS1_MAGIC
 248 #elif defined(UFS2_ONLY)
 249                             (fs.fs_magic == FS_UFS2_MAGIC &&
 250                             fs.fs_sblockloc == sblock_try[n])
 251 #else
 252                             fs.fs_magic == FS_UFS1_MAGIC ||
 253                             (fs.fs_magic == FS_UFS2_MAGIC &&
 254                             fs.fs_sblockloc == sblock_try[n])
 255 #endif
 256                             ) &&
 257                             fs.fs_bsize <= MAXBSIZE &&
 258                             fs.fs_bsize >= (int32_t)sizeof(struct fs))
 259                                 break;
 260                 }
 261                 if (sblock_try[n] == -1) {
 262                         return -1;
 263                 }
 264                 dsk_meta++;
 265         } else
 266                 memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
 267         if (!inode)
 268                 return 0;
 269         if (inomap != inode) {
 270                 n = IPERVBLK(&fs);
 271                 if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
 272                         return -1;
 273                 n = INO_TO_VBO(n, inode);
 274 #if defined(UFS1_ONLY)
 275                 memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
 276                     sizeof(dp1));
 277 #elif defined(UFS2_ONLY)
 278                 memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
 279                     sizeof(dp2));
 280 #else
 281                 if (fs.fs_magic == FS_UFS1_MAGIC)
 282                         memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
 283                             sizeof(dp1));
 284                 else
 285                         memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
 286                             sizeof(dp2));
 287 #endif
 288                 inomap = inode;
 289                 fs_off = 0;
 290                 blkmap = indmap = 0;
 291         }
 292         s = buf;
 293         size = DIP(di_size);
 294         n = size - fs_off;
 295         if (nbyte > n)
 296                 nbyte = n;
 297         nb = nbyte;
 298         while (nb) {
 299                 lbn = lblkno(&fs, fs_off);
 300                 off = blkoff(&fs, fs_off);
 301                 if (lbn < NDADDR) {
 302                         addr2 = DIP(di_db[lbn]);
 303                 } else if (lbn < NDADDR + NINDIR(&fs)) {
 304                         n = INDIRPERVBLK(&fs);
 305                         addr2 = DIP(di_ib[0]);
 306                         u = (u_int)(lbn - NDADDR) / n * DBPERVBLK;
 307                         vbaddr = fsbtodb(&fs, addr2) + u;
 308                         if (indmap != vbaddr) {
 309                                 if (dskread(indbuf, vbaddr, DBPERVBLK))
 310                                         return -1;
 311                                 indmap = vbaddr;
 312                         }
 313                         n = (lbn - NDADDR) & (n - 1);
 314 #if defined(UFS1_ONLY)
 315                         memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
 316                             sizeof(ufs1_daddr_t));
 317                         addr2 = addr1;
 318 #elif defined(UFS2_ONLY)
 319                         memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
 320                             sizeof(ufs2_daddr_t));
 321 #else
 322                         if (fs.fs_magic == FS_UFS1_MAGIC) {
 323                                 memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
 324                                     sizeof(ufs1_daddr_t));
 325                                 addr2 = addr1;
 326                         } else
 327                                 memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
 328                                     sizeof(ufs2_daddr_t));
 329 #endif
 330                 } else
 331                         return -1;
 332                 vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
 333                 vboff = off & VBLKMASK;
 334                 n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
 335                 if (n > VBLKSIZE)
 336                         n = VBLKSIZE;
 337                 if (blkmap != vbaddr) {
 338                         if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
 339                                 return -1;
 340                         blkmap = vbaddr;
 341                 }
 342                 n -= vboff;
 343                 if (n > nb)
 344                         n = nb;
 345                 memcpy(s, blkbuf + vboff, n);
 346                 s += n;
 347                 fs_off += n;
 348                 nb -= n;
 349         }
 350
 351         if (fsizep != NULL)
 352                 *fsizep = size;
 353
 354         return nbyte;
 355 }
 356
 357 static ssize_t
 358 fsread(ufs_ino_t inode, void *buf, size_t nbyte)
 359 {
 360
 361         return fsread_size(inode, buf, nbyte, NULL);
 362 }
 363