usr.sbin/installboot/ext2fs.c

   1 /*      $NetBSD: ext2fs.c,v 1.4 2009/10/19 18:41:17 bouyer Exp $        */
   2
   3 /*
   4  * Copyright (c) 1997 Manuel Bouyer.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 /*-
  28  * Copyright (c) 2002 The NetBSD Foundation, Inc.
  29  * All rights reserved.
  30  *
  31  * This code is derived from software contributed to The NetBSD Foundation
  32  * by Matt Fredette.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  44  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  45  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  46  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  47  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  48  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  49  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  50  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  51  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  52  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  53  * POSSIBILITY OF SUCH DAMAGE.
  54  */
  55
  56 #if HAVE_NBTOOL_CONFIG_H
  57 #include "nbtool_config.h"
  58 #endif
  59
  60 #include <sys/cdefs.h>
  61 #if defined(__RCSID) && !defined(__lint)
  62 __RCSID("$NetBSD: ext2fs.c,v 1.4 2009/10/19 18:41:17 bouyer Exp $");
  63 #endif  /* !__lint */
  64
  65 #include <sys/param.h>
  66
  67 #if !HAVE_NBTOOL_CONFIG_H
  68 #include <sys/mount.h>
  69 #endif
  70
  71 #include <assert.h>
  72 #include <err.h>
  73 #include <errno.h>
  74 #include <fcntl.h>
  75 #include <stdarg.h>
  76 #include <stdio.h>
  77 #include <stdlib.h>
  78 #include <string.h>
  79 #include <unistd.h>
  80
  81 #include "installboot.h"
  82
  83 #include <ufs/ext2fs/ext2fs_dinode.h>
  84 #include <ufs/ext2fs/ext2fs_dir.h>
  85 #include <ufs/ext2fs/ext2fs.h>
  86
  87 static int      ext2fs_read_disk_block(ib_params *, uint64_t, int, uint8_t []);
  88 static int      ext2fs_read_sblock(ib_params *, struct m_ext2fs *fs);
  89 static int      ext2fs_read_gdblock(ib_params *, struct m_ext2fs *fs);
  90 static int      ext2fs_find_disk_blocks(ib_params *, ino_t,
  91                     int (*)(ib_params *, void *, uint64_t, uint32_t), void *);
  92 static int      ext2fs_findstage2_ino(ib_params *, void *, uint64_t, uint32_t);
  93 static int      ext2fs_findstage2_blocks(ib_params *, void *, uint64_t,
  94                     uint32_t);
  95
  96
  97 /* This reads a disk block from the file system. */
  98 /* XXX: should be shared with ffs.c? */
  99 static int
 100 ext2fs_read_disk_block(ib_params *params, uint64_t blkno, int size,
 101     uint8_t blk[])
 102 {
 103         int rv;
 104
 105         assert(params != NULL);
 106         assert(params->filesystem != NULL);
 107         assert(params->fsfd != -1);
 108         assert(size > 0);
 109         assert(blk != NULL);
 110
 111         rv = pread(params->fsfd, blk, size, blkno * params->sectorsize);
 112         if (rv == -1) {
 113                 warn("Reading block %llu in `%s'",
 114                     (unsigned long long)blkno, params->filesystem);
 115                 return 0;
 116         } else if (rv != size) {
 117                 warnx("Reading block %llu in `%s': short read",
 118                     (unsigned long long)blkno, params->filesystem);
 119                 return 0;
 120         }
 121
 122         return 1;
 123 }
 124
 125 static int
 126 ext2fs_read_sblock(ib_params *params, struct m_ext2fs *fs)
 127 {
 128         uint8_t sbbuf[SBSIZE];
 129
 130         if (ext2fs_read_disk_block(params, SBOFF / params->sectorsize, SBSIZE,
 131             sbbuf) == 0)
 132
 133         e2fs_sbload((void *)sbbuf, &fs->e2fs);
 134
 135         if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
 136                 return 0;
 137
 138         if (fs->e2fs.e2fs_rev > E2FS_REV1 ||
 139             (fs->e2fs.e2fs_rev == E2FS_REV1 &&
 140              (fs->e2fs.e2fs_first_ino != EXT2_FIRSTINO ||
 141               fs->e2fs.e2fs_inode_size != EXT2_DINODE_SIZE ||
 142               (fs->e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP) != 0)))
 143                 return 0;
 144
 145         fs->e2fs_ncg =
 146             howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
 147             fs->e2fs.e2fs_bpg);
 148         /* XXX assume hw bsize = 512 */
 149         fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
 150         fs->e2fs_bsize = MINBSIZE << fs->e2fs.e2fs_log_bsize;
 151         fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
 152         fs->e2fs_qbmask = fs->e2fs_bsize - 1;
 153         fs->e2fs_bmask = ~fs->e2fs_qbmask;
 154         fs->e2fs_ngdb =
 155             howmany(fs->e2fs_ncg, fs->e2fs_bsize / sizeof(struct ext2_gd));
 156         fs->e2fs_ipb = fs->e2fs_bsize / EXT2_DINODE_SIZE;
 157         fs->e2fs_itpg = fs->e2fs.e2fs_ipg / fs->e2fs_ipb;
 158
 159         return 1;
 160 }
 161
 162 static int
 163 ext2fs_read_gdblock(ib_params *params, struct m_ext2fs *fs)
 164 {
 165         uint8_t gdbuf[MAXBSIZE];
 166         uint32_t gdpb;
 167         int i;
 168
 169         gdpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
 170
 171         for (i = 0; i < fs->e2fs_ngdb; i++) {
 172                 if (ext2fs_read_disk_block(params, fsbtodb(fs,
 173                     fs->e2fs.e2fs_first_dblock + 1 /* superblock */ + i),
 174                     SBSIZE, gdbuf) == 0)
 175                         return 0;
 176
 177                 e2fs_cgload((struct ext2_gd *)gdbuf, &fs->e2fs_gd[gdpb * i],
 178                     (i == (fs->e2fs_ngdb - 1)) ?
 179                     (fs->e2fs_ncg - gdpb * i) * sizeof(struct ext2_gd):
 180                     fs->e2fs_bsize);
 181         }
 182
 183         return 1;
 184 }
 185
 186 /*
 187  * This iterates over the data blocks belonging to an inode,
 188  * making a callback each iteration with the disk block number
 189  * and the size.
 190  */
 191 static int
 192 ext2fs_find_disk_blocks(ib_params *params, ino_t ino,
 193         int (*callback)(ib_params *, void *, uint64_t, uint32_t),
 194         void *state)
 195 {
 196         uint8_t sbbuf[sizeof(struct m_ext2fs)];
 197         struct m_ext2fs *fs;
 198         uint8_t inodebuf[MAXBSIZE];
 199         struct ext2fs_dinode inode_store, *inode;
 200         int level_i;
 201         int32_t blk, lblk, nblk;
 202         int rv;
 203 #define LEVELS 4
 204         struct {
 205                 uint32_t *blknums;
 206                 unsigned long blkcount;
 207                 uint8_t diskbuf[MAXBSIZE];
 208         } level[LEVELS];
 209
 210         assert(params != NULL);
 211         assert(params->fstype != NULL);
 212         assert(callback != NULL);
 213         assert(state != NULL);
 214
 215         /* Read the superblock. */
 216         fs = (void *)sbbuf;
 217         if (ext2fs_read_sblock(params, fs) == 0)
 218                 return 0;
 219
 220         fs->e2fs_gd = malloc(sizeof(struct ext2_gd) * fs->e2fs_ncg);
 221         if (fs->e2fs_gd == NULL) {
 222                 warnx("Can't allocate memofy for group descriptors");
 223                 return 0;
 224         }
 225
 226         if (ext2fs_read_gdblock(params, fs) == 0) {
 227                 warnx("Can't read group descriptors");
 228                 return 0;
 229         }
 230
 231         if (fs->e2fs_ipb <= 0) {
 232                 warnx("Bad ipb %d in superblock in `%s'",
 233                     fs->e2fs_ipb, params->filesystem);
 234                 return 0;
 235         }
 236
 237         /* Read the inode. */
 238         if (ext2fs_read_disk_block(params,
 239                 fsbtodb(fs, ino_to_fsba(fs, ino)) + params->fstype->offset,
 240                 fs->e2fs_bsize, inodebuf))
 241                 return 0;
 242         inode = (void *)inodebuf;
 243         e2fs_iload(&inode[ino_to_fsbo(fs, ino)], &inode_store);
 244         inode = &inode_store;
 245
 246         /* Get the block count and initialize for our block walk. */
 247         nblk = howmany(inode->e2di_size, fs->e2fs_bsize);
 248         lblk = 0;
 249         level_i = 0;
 250         level[0].blknums = &inode->e2di_blocks[0];
 251         level[0].blkcount = NDADDR;
 252         level[1].blknums = &inode->e2di_blocks[NDADDR + 0];
 253         level[1].blkcount = 1;
 254         level[2].blknums = &inode->e2di_blocks[NDADDR + 1];
 255         level[2].blkcount = 1;
 256         level[3].blknums = &inode->e2di_blocks[NDADDR + 2];
 257         level[3].blkcount = 1;
 258
 259         /* Walk the data blocks. */
 260         while (nblk > 0) {
 261
 262                 /*
 263                  * If there are no more blocks at this indirection
 264                  * level, move up one indirection level and loop.
 265                  */
 266                 if (level[level_i].blkcount == 0) {
 267                         if (++level_i == LEVELS)
 268                                 break;
 269                         continue;
 270                 }
 271
 272                 /* Get the next block at this level. */
 273                 blk = fs2h32(*(level[level_i].blknums++));
 274                 level[level_i].blkcount--;
 275
 276 #if 0
 277                 fprintf(stderr, "ino %lu blk %lu level %d\n", ino, blk,
 278                     level_i);
 279 #endif
 280
 281                 /*
 282                  * If we're not at the direct level, descend one
 283                  * level, read in that level's new block list,
 284                  * and loop.
 285                  */
 286                 if (level_i > 0) {
 287                         level_i--;
 288                         if (blk == 0)
 289                                 memset(level[level_i].diskbuf, 0, MAXBSIZE);
 290                         else if (ext2fs_read_disk_block(params,
 291                                 fsbtodb(fs, blk) + params->fstype->offset,
 292                                 fs->e2fs_bsize, level[level_i].diskbuf) == 0)
 293                                 return 0;
 294                         /* XXX ondisk32 */
 295                         level[level_i].blknums =
 296                             (uint32_t *)level[level_i].diskbuf;
 297                         level[level_i].blkcount = NINDIR(fs);
 298                         continue;
 299                 }
 300
 301                 /* blk is the next direct level block. */
 302 #if 0
 303                 fprintf(stderr, "ino %lu db %lu blksize %lu\n", ino,
 304                     fsbtodb(fs, blk), sblksize(fs, inode->di_size, lblk));
 305 #endif
 306                 rv = (*callback)(params, state,
 307                     fsbtodb(fs, blk) + params->fstype->offset, fs->e2fs_bsize);
 308                 lblk++;
 309                 nblk--;
 310                 if (rv != 1)
 311                         return rv;
 312         }
 313
 314         if (nblk != 0) {
 315                 warnx("Inode %llu in `%s' ran out of blocks?",
 316                     (unsigned long long)ino, params->filesystem);
 317                 return 0;
 318         }
 319
 320         return 1;
 321 }
 322
 323 /*
 324  * This callback reads a block of the root directory,
 325  * searches for an entry for the secondary bootstrap,
 326  * and saves the inode number if one is found.
 327  */
 328 static int
 329 ext2fs_findstage2_ino(ib_params *params, void *_ino,
 330         uint64_t blk, uint32_t blksize)
 331 {
 332         uint8_t dirbuf[MAXBSIZE];
 333         struct ext2fs_direct *de, *ede;
 334         uint32_t ino;
 335
 336         assert(params != NULL);
 337         assert(params->fstype != NULL);
 338         assert(params->stage2 != NULL);
 339         assert(_ino != NULL);
 340
 341         /* Skip directory holes. */
 342         if (blk == 0)
 343                 return 1;
 344
 345         /* Read the directory block. */
 346         if (ext2fs_read_disk_block(params, blk, blksize, dirbuf) == 0)
 347                 return 0;
 348
 349         /* Loop over the directory entries. */
 350         de = (struct ext2fs_direct *)&dirbuf[0];
 351         ede = (struct ext2fs_direct *)&dirbuf[blksize];
 352         while (de < ede) {
 353                 ino = fs2h32(de->e2d_ino);
 354                 if (ino != 0 && strcmp(de->e2d_name, params->stage2) == 0) {
 355                         *((uint32_t *)_ino) = ino;
 356                         return (2);
 357                 }
 358                 if (fs2h16(de->e2d_reclen) == 0)
 359                         break;
 360                 de = (struct ext2fs_direct *)((char *)de +
 361                     fs2h16(de->e2d_reclen));
 362         }
 363
 364         return 1;
 365 }
 366
 367 struct findblks_state {
 368         uint32_t        maxblk;
 369         uint32_t        nblk;
 370         ib_block        *blocks;
 371 };
 372
 373 /* This callback records the blocks of the secondary bootstrap. */
 374 static int
 375 ext2fs_findstage2_blocks(ib_params *params, void *_state,
 376         uint64_t blk, uint32_t blksize)
 377 {
 378         struct findblks_state *state = _state;
 379
 380         assert(params != NULL);
 381         assert(params->stage2 != NULL);
 382         assert(_state != NULL);
 383
 384         if (state->nblk == state->maxblk) {
 385                 warnx("Secondary bootstrap `%s' has too many blocks (max %d)",
 386                     params->stage2, state->maxblk);
 387                 return (0);
 388         }
 389         state->blocks[state->nblk].block = blk;
 390         state->blocks[state->nblk].blocksize = blksize;
 391         state->nblk++;
 392         return 1;
 393 }
 394
 395 /*
 396  *      publicly visible functions
 397  */
 398
 399 int
 400 ext2fs_match(ib_params *params)
 401 {
 402         uint8_t sbbuf[sizeof(struct m_ext2fs)];
 403         struct m_ext2fs *fs;
 404
 405         assert(params != NULL);
 406         assert(params->fstype != NULL);
 407
 408         /* Read the superblock. */
 409         fs = (void *)sbbuf;
 410         if (ext2fs_read_sblock(params, fs) == 0)
 411                 return 0;
 412
 413         params->fstype->needswap = 0;
 414         params->fstype->blocksize = fs->e2fs_bsize;
 415         params->fstype->offset = 0;
 416
 417         return 1;
 418 }
 419
 420 int
 421 ext2fs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks)
 422 {
 423         int rv;
 424         uint32_t ino;
 425         struct findblks_state state;
 426
 427         assert(params != NULL);
 428         assert(params->stage2 != NULL);
 429         assert(maxblk != NULL);
 430         assert(blocks != NULL);
 431
 432         if (params->flags & IB_STAGE2START)
 433                 return hardcode_stage2(params, maxblk, blocks);
 434
 435         /* The secondary bootstrap must be clearly in /. */
 436         if (params->stage2[0] == '/')
 437                 params->stage2++;
 438         if (strchr(params->stage2, '/') != NULL) {
 439                 warnx("The secondary bootstrap `%s' must be in /",
 440                     params->stage2);
 441                 warnx("(Path must be relative to the file system in `%s')",
 442                     params->filesystem);
 443                 return 0;
 444         }
 445
 446         /* Get the inode number of the secondary bootstrap. */
 447         rv = ext2fs_find_disk_blocks(params, EXT2_ROOTINO,
 448             ext2fs_findstage2_ino, &ino);
 449         if (rv != 2) {
 450                 warnx("Could not find secondary bootstrap `%s' in `%s'",
 451                     params->stage2, params->filesystem);
 452                 warnx("(Path must be relative to the file system in `%s')",
 453                     params->filesystem);
 454                 return 0;
 455         }
 456
 457         /* Record the disk blocks of the secondary bootstrap. */
 458         state.maxblk = *maxblk;
 459         state.nblk = 0;
 460         state.blocks = blocks;
 461                 rv = ext2fs_find_disk_blocks(params, ino,
 462                     ext2fs_findstage2_blocks, &state);
 463         if (rv == 0)
 464                 return 0;
 465
 466         *maxblk = state.nblk;
 467         return 1;
 468 }