Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 1 | /* |
| 2 | * dir_iterate.c --- ext2fs directory iteration operations |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3 | * |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 4 | * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o. |
| 5 | * |
| 6 | * %Begin-Header% |
Theodore Ts'o | 543547a | 2010-05-17 21:31:56 -0400 | [diff] [blame] | 7 | * This file may be redistributed under the terms of the GNU Library |
| 8 | * General Public License, version 2. |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 9 | * %End-Header% |
| 10 | */ |
| 11 | |
Theodore Ts'o | d1154eb | 2011-09-18 17:34:37 -0400 | [diff] [blame] | 12 | #include "config.h" |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 13 | #include <stdio.h> |
| 14 | #include <string.h> |
Theodore Ts'o | 4cbe8af | 1997-08-10 23:07:40 +0000 | [diff] [blame] | 15 | #if HAVE_UNISTD_H |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 16 | #include <unistd.h> |
Theodore Ts'o | 4cbe8af | 1997-08-10 23:07:40 +0000 | [diff] [blame] | 17 | #endif |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 18 | #if HAVE_ERRNO_H |
| 19 | #include <errno.h> |
| 20 | #endif |
| 21 | |
Theodore Ts'o | b5abe6f | 1998-01-19 14:47:53 +0000 | [diff] [blame] | 22 | #include "ext2_fs.h" |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 23 | #include "ext2fsP.h" |
| 24 | |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 25 | #define EXT4_MAX_REC_LEN ((1<<16)-1) |
| 26 | |
| 27 | errcode_t ext2fs_get_rec_len(ext2_filsys fs, |
| 28 | struct ext2_dir_entry *dirent, |
| 29 | unsigned int *rec_len) |
| 30 | { |
| 31 | unsigned int len = dirent->rec_len; |
| 32 | |
Theodore Ts'o | a4fdf09 | 2010-12-22 13:53:02 -0500 | [diff] [blame] | 33 | if (fs->blocksize < 65536) |
| 34 | *rec_len = len; |
| 35 | else if (len == EXT4_MAX_REC_LEN || len == 0) |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 36 | *rec_len = fs->blocksize; |
| 37 | else |
| 38 | *rec_len = (len & 65532) | ((len & 3) << 16); |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | errcode_t ext2fs_set_rec_len(ext2_filsys fs, |
| 43 | unsigned int len, |
| 44 | struct ext2_dir_entry *dirent) |
| 45 | { |
| 46 | if ((len > fs->blocksize) || (fs->blocksize > (1 << 18)) || (len & 3)) |
| 47 | return EINVAL; |
| 48 | if (len < 65536) { |
| 49 | dirent->rec_len = len; |
| 50 | return 0; |
| 51 | } |
| 52 | if (len == fs->blocksize) { |
| 53 | if (fs->blocksize == 65536) |
| 54 | dirent->rec_len = EXT4_MAX_REC_LEN; |
| 55 | else |
| 56 | dirent->rec_len = 0; |
| 57 | } else |
| 58 | dirent->rec_len = (len & 65532) | ((len >> 16) & 3); |
| 59 | return 0; |
| 60 | } |
| 61 | |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 62 | /* |
| 63 | * This function checks to see whether or not a potential deleted |
| 64 | * directory entry looks valid. What we do is check the deleted entry |
| 65 | * and each successive entry to make sure that they all look valid and |
| 66 | * that the last deleted entry ends at the beginning of the next |
| 67 | * undeleted entry. Returns 1 if the deleted entry looks valid, zero |
| 68 | * if not valid. |
| 69 | */ |
Nic Case | 6a8da46 | 2009-06-29 01:24:40 -0400 | [diff] [blame] | 70 | static int ext2fs_validate_entry(ext2_filsys fs, char *buf, |
| 71 | unsigned int offset, |
| 72 | unsigned int final_offset) |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 73 | { |
| 74 | struct ext2_dir_entry *dirent; |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 75 | unsigned int rec_len; |
Nic Case | 6a8da46 | 2009-06-29 01:24:40 -0400 | [diff] [blame] | 76 | #define DIRENT_MIN_LENGTH 12 |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 77 | |
Nic Case | 6a8da46 | 2009-06-29 01:24:40 -0400 | [diff] [blame] | 78 | while ((offset < final_offset) && |
| 79 | (offset <= fs->blocksize - DIRENT_MIN_LENGTH)) { |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 80 | dirent = (struct ext2_dir_entry *)(buf + offset); |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 81 | if (ext2fs_get_rec_len(fs, dirent, &rec_len)) |
| 82 | return 0; |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 83 | offset += rec_len; |
| 84 | if ((rec_len < 8) || |
| 85 | ((rec_len % 4) != 0) || |
Theodore Ts'o | 25c7e0c | 2009-07-12 01:13:06 -0400 | [diff] [blame] | 86 | ((((unsigned) dirent->name_len & 0xFF)+8) > rec_len)) |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 87 | return 0; |
| 88 | } |
| 89 | return (offset == final_offset); |
| 90 | } |
| 91 | |
| 92 | errcode_t ext2fs_dir_iterate2(ext2_filsys fs, |
| 93 | ext2_ino_t dir, |
| 94 | int flags, |
| 95 | char *block_buf, |
| 96 | int (*func)(ext2_ino_t dir, |
| 97 | int entry, |
| 98 | struct ext2_dir_entry *dirent, |
| 99 | int offset, |
| 100 | int blocksize, |
| 101 | char *buf, |
| 102 | void *priv_data), |
| 103 | void *priv_data) |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 104 | { |
| 105 | struct dir_context ctx; |
| 106 | errcode_t retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 107 | |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 108 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| 109 | |
| 110 | retval = ext2fs_check_directory(fs, dir); |
| 111 | if (retval) |
| 112 | return retval; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 113 | |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 114 | ctx.dir = dir; |
| 115 | ctx.flags = flags; |
| 116 | if (block_buf) |
| 117 | ctx.buf = block_buf; |
| 118 | else { |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 119 | retval = ext2fs_get_mem(fs->blocksize, &ctx.buf); |
Theodore Ts'o | 7b4e453 | 1997-10-26 03:41:24 +0000 | [diff] [blame] | 120 | if (retval) |
| 121 | return retval; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 122 | } |
| 123 | ctx.func = func; |
Theodore Ts'o | b5abe6f | 1998-01-19 14:47:53 +0000 | [diff] [blame] | 124 | ctx.priv_data = priv_data; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 125 | ctx.errcode = 0; |
Theodore Ts'o | ab13b5a | 2010-06-13 10:00:00 -0400 | [diff] [blame] | 126 | retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_READ_ONLY, 0, |
Theodore Ts'o | 36a43d6 | 1998-03-24 16:17:51 +0000 | [diff] [blame] | 127 | ext2fs_process_dir_block, &ctx); |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 128 | if (!block_buf) |
Theodore Ts'o | c4e3d3f | 2003-08-01 09:41:07 -0400 | [diff] [blame] | 129 | ext2fs_free_mem(&ctx.buf); |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 130 | if (retval) |
| 131 | return retval; |
| 132 | return ctx.errcode; |
| 133 | } |
| 134 | |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 135 | struct xlate { |
| 136 | int (*func)(struct ext2_dir_entry *dirent, |
| 137 | int offset, |
| 138 | int blocksize, |
| 139 | char *buf, |
| 140 | void *priv_data); |
| 141 | void *real_private; |
| 142 | }; |
| 143 | |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 144 | static int xlate_func(ext2_ino_t dir EXT2FS_ATTR((unused)), |
| 145 | int entry EXT2FS_ATTR((unused)), |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 146 | struct ext2_dir_entry *dirent, int offset, |
| 147 | int blocksize, char *buf, void *priv_data) |
| 148 | { |
| 149 | struct xlate *xl = (struct xlate *) priv_data; |
| 150 | |
| 151 | return (*xl->func)(dirent, offset, blocksize, buf, xl->real_private); |
| 152 | } |
| 153 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 154 | extern errcode_t ext2fs_dir_iterate(ext2_filsys fs, |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 155 | ext2_ino_t dir, |
| 156 | int flags, |
| 157 | char *block_buf, |
| 158 | int (*func)(struct ext2_dir_entry *dirent, |
| 159 | int offset, |
| 160 | int blocksize, |
| 161 | char *buf, |
| 162 | void *priv_data), |
| 163 | void *priv_data) |
| 164 | { |
| 165 | struct xlate xl; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 166 | |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 167 | xl.real_private = priv_data; |
| 168 | xl.func = func; |
| 169 | |
| 170 | return ext2fs_dir_iterate2(fs, dir, flags, block_buf, |
| 171 | xlate_func, &xl); |
| 172 | } |
| 173 | |
| 174 | |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 175 | /* |
| 176 | * Helper function which is private to this module. Used by |
| 177 | * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate() |
| 178 | */ |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 179 | int ext2fs_process_dir_block(ext2_filsys fs, |
Theodore Ts'o | ab13b5a | 2010-06-13 10:00:00 -0400 | [diff] [blame] | 180 | blk64_t *blocknr, |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 181 | e2_blkcnt_t blockcnt, |
Theodore Ts'o | ab13b5a | 2010-06-13 10:00:00 -0400 | [diff] [blame] | 182 | blk64_t ref_block EXT2FS_ATTR((unused)), |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 183 | int ref_offset EXT2FS_ATTR((unused)), |
| 184 | void *priv_data) |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 185 | { |
Theodore Ts'o | b5abe6f | 1998-01-19 14:47:53 +0000 | [diff] [blame] | 186 | struct dir_context *ctx = (struct dir_context *) priv_data; |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 187 | unsigned int offset = 0; |
| 188 | unsigned int next_real_entry = 0; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 189 | int ret = 0; |
| 190 | int changed = 0; |
| 191 | int do_abort = 0; |
Theodore Ts'o | 25c7e0c | 2009-07-12 01:13:06 -0400 | [diff] [blame] | 192 | unsigned int rec_len, size; |
| 193 | int entry; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 194 | struct ext2_dir_entry *dirent; |
| 195 | |
| 196 | if (blockcnt < 0) |
| 197 | return 0; |
| 198 | |
Theodore Ts'o | 36a43d6 | 1998-03-24 16:17:51 +0000 | [diff] [blame] | 199 | entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 200 | |
Theodore Ts'o | ab13b5a | 2010-06-13 10:00:00 -0400 | [diff] [blame] | 201 | ctx->errcode = ext2fs_read_dir_block3(fs, *blocknr, ctx->buf, 0); |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 202 | if (ctx->errcode) |
| 203 | return BLOCK_ABORT; |
| 204 | |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 205 | while (offset < fs->blocksize) { |
| 206 | dirent = (struct ext2_dir_entry *) (ctx->buf + offset); |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 207 | if (ext2fs_get_rec_len(fs, dirent, &rec_len)) |
| 208 | return BLOCK_ABORT; |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 209 | if (((offset + rec_len) > fs->blocksize) || |
| 210 | (rec_len < 8) || |
| 211 | ((rec_len % 4) != 0) || |
Theodore Ts'o | 25c7e0c | 2009-07-12 01:13:06 -0400 | [diff] [blame] | 212 | ((((unsigned) dirent->name_len & 0xFF)+8) > rec_len)) { |
Theodore Ts'o | 813bbb2 | 1999-06-22 03:17:45 +0000 | [diff] [blame] | 213 | ctx->errcode = EXT2_ET_DIR_CORRUPTED; |
| 214 | return BLOCK_ABORT; |
| 215 | } |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 216 | if (!dirent->inode && |
| 217 | !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY)) |
| 218 | goto next; |
| 219 | |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 220 | ret = (ctx->func)(ctx->dir, |
| 221 | (next_real_entry > offset) ? |
| 222 | DIRENT_DELETED_FILE : entry, |
| 223 | dirent, offset, |
| 224 | fs->blocksize, ctx->buf, |
| 225 | ctx->priv_data); |
| 226 | if (entry < DIRENT_OTHER_FILE) |
| 227 | entry++; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 228 | |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 229 | if (ret & DIRENT_CHANGED) { |
Theodore Ts'o | 8a48035 | 2009-06-21 21:07:38 -0400 | [diff] [blame] | 230 | if (ext2fs_get_rec_len(fs, dirent, &rec_len)) |
| 231 | return BLOCK_ABORT; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 232 | changed++; |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 233 | } |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 234 | if (ret & DIRENT_ABORT) { |
| 235 | do_abort++; |
| 236 | break; |
| 237 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 238 | next: |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 239 | if (next_real_entry == offset) |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 240 | next_real_entry += rec_len; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 241 | |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 242 | if (ctx->flags & DIRENT_FLAG_INCLUDE_REMOVED) { |
| 243 | size = ((dirent->name_len & 0xFF) + 11) & ~3; |
| 244 | |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 245 | if (rec_len != size) { |
Theodore Ts'o | 5443492 | 2003-12-07 01:28:50 -0500 | [diff] [blame] | 246 | unsigned int final_offset; |
| 247 | |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 248 | final_offset = offset + rec_len; |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 249 | offset += size; |
| 250 | while (offset < final_offset && |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 251 | !ext2fs_validate_entry(fs, ctx->buf, |
Theodore Ts'o | 8bd0c95 | 2002-01-03 03:29:19 -0500 | [diff] [blame] | 252 | offset, |
| 253 | final_offset)) |
| 254 | offset += 4; |
| 255 | continue; |
| 256 | } |
| 257 | } |
Theodore Ts'o | 5dd77db | 2008-08-25 21:08:19 -0400 | [diff] [blame] | 258 | offset += rec_len; |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | if (changed) { |
Theodore Ts'o | ab13b5a | 2010-06-13 10:00:00 -0400 | [diff] [blame] | 262 | ctx->errcode = ext2fs_write_dir_block3(fs, *blocknr, ctx->buf, |
| 263 | 0); |
Theodore Ts'o | 21c84b7 | 1997-04-29 16:15:03 +0000 | [diff] [blame] | 264 | if (ctx->errcode) |
| 265 | return BLOCK_ABORT; |
| 266 | } |
| 267 | if (do_abort) |
| 268 | return BLOCK_ABORT; |
| 269 | return 0; |
| 270 | } |
| 271 | |