ffs.c revision 1.1
1 /* $NetBSD: ffs.c,v 1.1 2002/04/19 07:08:51 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Fredette. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(__RCSID) && !defined(__lint) 41 __RCSID("$NetBSD: ffs.c,v 1.1 2002/04/19 07:08:51 lukem Exp $"); 42 #endif /* !__lint */ 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 47 #include <assert.h> 48 #include <err.h> 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 #include "installboot.h" 58 59 #undef DIRBLKSIZ 60 61 #include <ufs/ufs/dinode.h> 62 #include <ufs/ufs/dir.h> 63 #include <ufs/ffs/fs.h> 64 #include <ufs/ffs/ffs_extern.h> 65 #include <ufs/ufs/ufs_bswap.h> 66 67 /* This reads a disk block from the filesystem. */ 68 static int 69 ffs_read_disk_block(ib_params *params, uint32_t blkno, int size, char *blk) 70 { 71 int rv; 72 73 assert(params->filesystem != NULL); 74 assert(params->fsfd != -1); 75 assert(blkno > 0); 76 assert(size > 0); 77 assert(blk != NULL); 78 79 rv = pread(params->fsfd, blk, size, blkno * DEV_BSIZE); 80 if (rv == -1) { 81 warn("Reading block %d in `%s'", blkno, params->filesystem); 82 return (0); 83 } else if (rv != size) { 84 warnx("Reading block %d in `%s': short read", blkno, 85 params->filesystem); 86 return (0); 87 } 88 89 return (1); 90 } 91 92 /* 93 * This iterates over the data blocks belonging to an inode, 94 * making a callback each iteration with the disk block number 95 * and the size. 96 */ 97 static int 98 ffs_find_disk_blocks(ib_params *params, uint32_t ino, 99 int (*callback)(ib_params *, void *, uint32_t, uint32_t, int), 100 void *state) 101 { 102 char sbbuf[SBSIZE]; 103 struct fs *fs; 104 int needswap; 105 char inodebuf[MAXBSIZE]; 106 struct dinode *inode; 107 int level_i; 108 ufs_daddr_t blk, lblk, nblk; 109 int rv; 110 #define LEVELS 4 111 struct { 112 ufs_daddr_t *blknums; 113 unsigned long blkcount; 114 char diskbuf[MAXBSIZE]; 115 } level[LEVELS]; 116 117 /* Read the superblock. */ 118 if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf)) 119 return (0); 120 fs = (struct fs *)sbbuf; 121 needswap = 0; 122 if (fs->fs_magic == htole32(FS_MAGIC)) { 123 #if BYTE_ORDER == BIG_ENDIAN 124 needswap = 1; 125 #endif 126 } else if (fs->fs_magic == htobe32(FS_MAGIC)) { 127 #if BYTE_ORDER == LITTLE_ENDIAN 128 needswap = 1; 129 #endif 130 } else 131 return (0); 132 if (needswap) 133 ffs_sb_swap(fs, fs); 134 135 /* Sanity check the superblock. */ 136 if (fs->fs_magic != FS_MAGIC) { 137 warnx("Bad superblock magic number in `%s'", 138 params->filesystem); 139 return (0); 140 } 141 if (fs->fs_inopb <= 0) { 142 warnx("Bad inopb %d in superblock in `%s'", 143 fs->fs_inopb, params->filesystem); 144 return (0); 145 } 146 147 /* Read the inode. */ 148 if (! ffs_read_disk_block(params, fsbtodb(fs, ino_to_fsba(fs, ino)), 149 fs->fs_bsize, inodebuf)) 150 return (0); 151 inode = (struct dinode *)inodebuf; 152 inode += ino_to_fsbo(fs, ino); 153 if (needswap) 154 ffs_dinode_swap(inode, inode); 155 156 /* Get the block count and initialize for our block walk. */ 157 nblk = howmany(inode->di_size, fs->fs_bsize); 158 lblk = 0; 159 level_i = 0; 160 level[0].blknums = &inode->di_db[0]; 161 level[0].blkcount = NDADDR; 162 level[1].blknums = &inode->di_ib[0]; 163 level[1].blkcount = 1; 164 level[2].blknums = &inode->di_ib[1]; 165 level[2].blkcount = 1; 166 level[3].blknums = &inode->di_ib[2]; 167 level[3].blkcount = 1; 168 169 /* Walk the data blocks. */ 170 while (nblk > 0) { 171 172 /* 173 * If there are no more blocks at this indirection 174 * level, move up one indirection level and loop. 175 */ 176 if (level[level_i].blkcount == 0) { 177 if (++level_i == LEVELS) 178 break; 179 continue; 180 } 181 182 /* Get the next block at this level. */ 183 blk = *(level[level_i].blknums++); 184 level[level_i].blkcount--; 185 if (needswap) 186 blk = bswap32(blk); 187 188 #if 0 189 fprintf(stderr, "ino %lu blk %lu level %d\n", ino, blk, 190 level_i); 191 #endif 192 193 /* 194 * If we're not at the direct level, descend one 195 * level, read in that level's new block list, 196 * and loop. 197 */ 198 if (level_i > 0) { 199 level_i--; 200 if (blk == 0) 201 memset(level[level_i].diskbuf, 0, MAXBSIZE); 202 else if (! ffs_read_disk_block(params, 203 fsbtodb(fs, blk), 204 fs->fs_bsize, level[level_i].diskbuf)) 205 return (0); 206 level[level_i].blknums = 207 (ufs_daddr_t *)level[level_i].diskbuf; 208 level[level_i].blkcount = NINDIR(fs); 209 continue; 210 } 211 212 /* blk is the next direct level block. */ 213 #if 0 214 fprintf(stderr, "ino %lu db %lu blksize %lu\n", ino, 215 fsbtodb(fs, blk), dblksize(fs, inode, lblk)); 216 #endif 217 rv = (*callback)(params, state, 218 fsbtodb(fs, blk), dblksize(fs, inode, lblk), needswap); 219 lblk++; 220 nblk--; 221 if (rv != 1) 222 return (rv); 223 } 224 225 if (nblk != 0) { 226 warnx("Inode %d in `%s' ran out of blocks?", ino, 227 params->filesystem); 228 return (0); 229 } 230 231 return (1); 232 } 233 234 /* 235 * This callback reads a block of the root directory, 236 * searches for an entry for the secondary bootstrap, 237 * and saves the inode number if one is found. 238 */ 239 static int 240 ffs_findstage2_ino(ib_params *params, void *_ino, 241 uint32_t blk, uint32_t blksize, int needswap) 242 { 243 char dirbuf[MAXBSIZE]; 244 struct direct *de, *ede; 245 uint32_t ino; 246 247 /* Skip directory holes. */ 248 if (blk == 0) 249 return (1); 250 251 /* Read the directory block. */ 252 if (! ffs_read_disk_block(params, blk, blksize, dirbuf)) 253 return (0); 254 255 /* Loop over the directory entries. */ 256 de = (struct direct *)&dirbuf[0]; 257 ede = (struct direct *)&dirbuf[blksize]; 258 while (de < ede) { 259 ino = de->d_ino; 260 if (needswap) { 261 ino = bswap32(ino); 262 de->d_reclen = bswap16(de->d_reclen); 263 } 264 if (ino != 0 && strcmp(de->d_name, params->stage2) == 0) { 265 *((uint32_t *)_ino) = ino; 266 return (2); 267 } 268 de = (struct direct *)((char *)de + de->d_reclen); 269 } 270 271 return (1); 272 } 273 274 struct findblks_state { 275 uint32_t maxblk; 276 uint32_t nblk; 277 ib_block *blocks; 278 }; 279 280 /* This callback records the blocks of the secondary bootstrap. */ 281 static int 282 ffs_findstage2_blocks(ib_params *params, void *_state, 283 uint32_t blk, uint32_t blksize, int needswap) 284 { 285 struct findblks_state *state = _state; 286 287 if (state->nblk == state->maxblk) { 288 warnx("Secondary bootstrap `%s' has too many blocks " \ 289 "(max %d)\n", params->stage2, state->maxblk); 290 return (0); 291 } 292 state->blocks[state->nblk].block = blk; 293 state->blocks[state->nblk].blocksize = blksize; 294 state->nblk++; 295 return (1); 296 } 297 298 /* publically visible functions */ 299 300 int 301 ffs_match(ib_params *params) 302 { 303 char sbbuf[SBSIZE]; 304 struct fs *fs; 305 306 /* Read and check the superblock. */ 307 if (! ffs_read_disk_block(params, SBLOCK, SBSIZE, sbbuf)) 308 return (0); 309 fs = (struct fs *)sbbuf; 310 if (fs->fs_magic == htole32(FS_MAGIC) || 311 fs->fs_magic == htobe32(FS_MAGIC)) 312 return (1); 313 314 return (0); 315 } 316 317 int 318 ffs_findstage2(ib_params *params, uint32_t *maxblk, ib_block *blocks) 319 { 320 int rv; 321 uint32_t ino; 322 struct findblks_state state; 323 324 assert (params->stage2 != NULL); 325 326 /* The secondary bootstrap must be clearly in /. */ 327 if (params->stage2[0] == '/') 328 params->stage2++; 329 if (strchr(params->stage2, '/') != NULL) { 330 warnx("The secondary bootstrap `%s' must be in /", 331 params->stage2); 332 return (0); 333 } 334 335 /* Get the inode number of the secondary bootstrap. */ 336 rv = ffs_find_disk_blocks(params, ROOTINO, ffs_findstage2_ino, &ino); 337 if (rv != 2) 338 return (0); 339 340 /* Record the disk blocks of the secondary bootstrap. */ 341 state.maxblk = *maxblk; 342 state.nblk = 0; 343 state.blocks = blocks; 344 rv = ffs_find_disk_blocks(params, ino, ffs_findstage2_blocks, &state); 345 if (! rv) 346 return (0); 347 348 *maxblk = state.nblk; 349 return (1); 350 } 351
Indexes created Sat Sep 27 14:09:57 GMT 2025