1 /*
2 * swapfs.c --- swap ext2 filesystem data structures
3 *
4 * Copyright (C) 1995, 1996, 2002 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12 #include "config.h"
13 #include <stdio.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <string.h>
18 #include <time.h>
19
20 #include "ext2_fs.h"
21 #include "ext2fs.h"
22 #include "ext2fsP.h"
23 #include <ext2fs/ext2_ext_attr.h>
24
ext2fs_swap_super(struct ext2_super_block * sb)25 void ext2fs_swap_super(struct ext2_super_block * sb)
26 {
27 int i;
28
29 sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
30 sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
31 sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
32 sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
33 sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
34 sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
35 sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
36 sb->s_log_cluster_size = ext2fs_swab32(sb->s_log_cluster_size);
37 sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
38 sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_per_group);
39 sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
40 sb->s_mtime = ext2fs_swab32(sb->s_mtime);
41 sb->s_wtime = ext2fs_swab32(sb->s_wtime);
42 sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
43 sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
44 sb->s_magic = ext2fs_swab16(sb->s_magic);
45 sb->s_state = ext2fs_swab16(sb->s_state);
46 sb->s_errors = ext2fs_swab16(sb->s_errors);
47 sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
48 sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
49 sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
50 sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
51 sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
52 sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
53 sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
54 sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
55 sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
56 sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
57 sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
58 sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
59 sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
60 /* sb->s_uuid is __u8 and does not need swabbing */
61 /* sb->s_volume_name is char and does not need swabbing */
62 /* sb->s_last_mounted is char and does not need swabbing */
63 sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
64 /* sb->s_prealloc_blocks is __u8 and does not need swabbing */
65 /* sb->s_prealloc_dir_blocks is __u8 and does not need swabbing */
66 sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
67 /* sb->s_journal_uuid is __u8 and does not need swabbing */
68 sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
69 sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
70 sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
71 for (i = 0; i < 4; i++)
72 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
73 /* sb->s_def_hash_version is __u8 and does not need swabbing */
74 /* sb->s_jnl_backup_type is __u8 and does not need swabbing */
75 sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
76 sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
77 sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
78 sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
79 /* if journal backup is for a valid extent-based journal... */
80 if (ext2fs_extent_header_verify(sb->s_jnl_blocks,
81 sizeof(sb->s_jnl_blocks)) == 0) {
82 /* ... swap only the journal i_size and i_size_high,
83 * and the extent data is not swapped on read */
84 i = 15;
85 } else {
86 /* direct/indirect journal: swap it all */
87 i = 0;
88 }
89 for (; i < 17; i++)
90 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
91 sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
92 sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
93 sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
94 sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
95 sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
96 sb->s_flags = ext2fs_swab32(sb->s_flags);
97 sb->s_raid_stride = ext2fs_swab16(sb->s_raid_stride);
98 sb->s_mmp_update_interval = ext2fs_swab16(sb->s_mmp_update_interval);
99 sb->s_mmp_block = ext2fs_swab64(sb->s_mmp_block);
100 sb->s_raid_stripe_width = ext2fs_swab32(sb->s_raid_stripe_width);
101 /* sb->s_log_groups_per_flex is __u8 and does not need swabbing */
102 /* sb->s_checksum_type is __u8 and does not need swabbing */
103 /* sb->s_encryption_level is __u8 and does not need swabbing */
104 /* sb->s_reserved_pad is __u8 and does not need swabbing */
105 sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
106 sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
107 sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
108 sb->s_snapshot_r_blocks_count =
109 ext2fs_swab64(sb->s_snapshot_r_blocks_count);
110 sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
111 sb->s_error_count = ext2fs_swab32(sb->s_error_count);
112 sb->s_first_error_time = ext2fs_swab32(sb->s_first_error_time);
113 sb->s_first_error_ino = ext2fs_swab32(sb->s_first_error_ino);
114 sb->s_first_error_block = ext2fs_swab64(sb->s_first_error_block);
115 /* sb->s_first_error_func is __u8 and does not need swabbing */
116 sb->s_last_error_time = ext2fs_swab32(sb->s_last_error_time);
117 sb->s_last_error_ino = ext2fs_swab32(sb->s_last_error_ino);
118 sb->s_last_error_block = ext2fs_swab64(sb->s_last_error_block);
119 /* sb->s_last_error_func is __u8 and does not need swabbing */
120 /* sb->s_mount_opts is __u8 and does not need swabbing */
121 sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
122 sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
123 sb->s_overhead_clusters = ext2fs_swab32(sb->s_overhead_clusters);
124 sb->s_backup_bgs[0] = ext2fs_swab32(sb->s_backup_bgs[0]);
125 sb->s_backup_bgs[1] = ext2fs_swab32(sb->s_backup_bgs[1]);
126 /* sb->s_encrypt_algos is __u8 and does not need swabbing */
127 /* sb->s_encrypt_pw_salt is __u8 and does not need swabbing */
128 sb->s_lpf_ino = ext2fs_swab32(sb->s_lpf_ino);
129 sb->s_prj_quota_inum = ext2fs_swab32(sb->s_prj_quota_inum);
130 sb->s_checksum_seed = ext2fs_swab32(sb->s_checksum_seed);
131 /* s_*_time_hi are __u8 and does not need swabbing */
132 sb->s_encoding = ext2fs_swab16(sb->s_encoding);
133 sb->s_encoding_flags = ext2fs_swab16(sb->s_encoding_flags);
134 /* catch when new fields are used from s_reserved */
135 EXT2FS_BUILD_BUG_ON(sizeof(sb->s_reserved) != 95 * sizeof(__le32));
136 sb->s_checksum = ext2fs_swab32(sb->s_checksum);
137 }
138
ext2fs_swap_group_desc2(ext2_filsys fs,struct ext2_group_desc * gdp)139 void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
140 {
141 struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
142
143 /* Do the 32-bit parts first */
144 gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
145 gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
146 gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
147 gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
148 gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
149 gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
150 gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
151 gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
152 gdp->bg_block_bitmap_csum_lo =
153 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
154 gdp->bg_inode_bitmap_csum_lo =
155 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
156 gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
157 gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
158 /* If we're 32-bit, we're done */
159 if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
160 return;
161
162 /* Swap the 64-bit parts */
163 gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
164 gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
165 gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
166 gdp4->bg_free_blocks_count_hi =
167 ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
168 gdp4->bg_free_inodes_count_hi =
169 ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
170 gdp4->bg_used_dirs_count_hi =
171 ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
172 gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
173 gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
174 gdp4->bg_block_bitmap_csum_hi =
175 ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
176 gdp4->bg_inode_bitmap_csum_hi =
177 ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
178 EXT2FS_BUILD_BUG_ON(sizeof(gdp4->bg_reserved) != sizeof(__u32));
179 }
180
ext2fs_swap_group_desc(struct ext2_group_desc * gdp)181 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
182 {
183 ext2fs_swap_group_desc2(0, gdp);
184 }
185
186
ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header * to_header,struct ext2_ext_attr_header * from_header)187 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
188 struct ext2_ext_attr_header *from_header)
189 {
190 int n;
191
192 to_header->h_magic = ext2fs_swab32(from_header->h_magic);
193 to_header->h_blocks = ext2fs_swab32(from_header->h_blocks);
194 to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
195 to_header->h_hash = ext2fs_swab32(from_header->h_hash);
196 to_header->h_checksum = ext2fs_swab32(from_header->h_checksum);
197 for (n = 0; n < 3; n++)
198 to_header->h_reserved[n] =
199 ext2fs_swab32(from_header->h_reserved[n]);
200 }
201
ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry * to_entry,struct ext2_ext_attr_entry * from_entry)202 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
203 struct ext2_ext_attr_entry *from_entry)
204 {
205 to_entry->e_value_offs = ext2fs_swab16(from_entry->e_value_offs);
206 to_entry->e_value_inum = ext2fs_swab32(from_entry->e_value_inum);
207 to_entry->e_value_size = ext2fs_swab32(from_entry->e_value_size);
208 to_entry->e_hash = ext2fs_swab32(from_entry->e_hash);
209 }
210
ext2fs_swap_ext_attr(char * to,char * from,int bufsize,int has_header)211 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
212 {
213 struct ext2_ext_attr_header *from_header =
214 (struct ext2_ext_attr_header *)from;
215 struct ext2_ext_attr_header *to_header =
216 (struct ext2_ext_attr_header *)to;
217 struct ext2_ext_attr_entry *from_entry, *to_entry;
218 char *from_end = (char *)from_header + bufsize;
219
220 if (to_header != from_header)
221 memcpy(to_header, from_header, bufsize);
222
223 if (has_header) {
224 ext2fs_swap_ext_attr_header(to_header, from_header);
225
226 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
227 to_entry = (struct ext2_ext_attr_entry *)(to_header+1);
228 } else {
229 from_entry = (struct ext2_ext_attr_entry *)from_header;
230 to_entry = (struct ext2_ext_attr_entry *)to_header;
231 }
232
233 while ((char *)from_entry < from_end &&
234 (char *)EXT2_EXT_ATTR_NEXT(from_entry) <= from_end &&
235 *(__u32 *)from_entry) {
236 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
237 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
238 to_entry = EXT2_EXT_ATTR_NEXT(to_entry);
239 }
240 }
241
ext2fs_swap_inode_full(ext2_filsys fs,struct ext2_inode_large * t,struct ext2_inode_large * f,int hostorder,int bufsize)242 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
243 struct ext2_inode_large *f, int hostorder,
244 int bufsize)
245 {
246 unsigned i, extra_isize, attr_magic;
247 int has_extents, has_inline_data, islnk, fast_symlink;
248 unsigned int inode_size;
249 __u32 *eaf, *eat;
250
251 /*
252 * Note that t and f may point to the same address. That's why
253 * if (hostorder) condition is executed before swab calls and
254 * if (!hostorder) afterwards.
255 */
256 if (hostorder) {
257 islnk = LINUX_S_ISLNK(f->i_mode);
258 fast_symlink = ext2fs_is_fast_symlink(EXT2_INODE(f));
259 has_extents = (f->i_flags & EXT4_EXTENTS_FL) != 0;
260 has_inline_data = (f->i_flags & EXT4_INLINE_DATA_FL) != 0;
261 }
262
263 t->i_mode = ext2fs_swab16(f->i_mode);
264 t->i_uid = ext2fs_swab16(f->i_uid);
265 t->i_size = ext2fs_swab32(f->i_size);
266 t->i_atime = ext2fs_swab32(f->i_atime);
267 t->i_ctime = ext2fs_swab32(f->i_ctime);
268 t->i_mtime = ext2fs_swab32(f->i_mtime);
269 t->i_dtime = ext2fs_swab32(f->i_dtime);
270 t->i_gid = ext2fs_swab16(f->i_gid);
271 t->i_links_count = ext2fs_swab16(f->i_links_count);
272 t->i_file_acl = ext2fs_swab32(f->i_file_acl);
273 t->i_blocks = ext2fs_swab32(f->i_blocks);
274 t->i_flags = ext2fs_swab32(f->i_flags);
275 t->i_size_high = ext2fs_swab32(f->i_size_high);
276
277 if (!hostorder) {
278 islnk = LINUX_S_ISLNK(t->i_mode);
279 fast_symlink = ext2fs_is_fast_symlink(EXT2_INODE(t));
280 has_extents = (t->i_flags & EXT4_EXTENTS_FL) != 0;
281 has_inline_data = (t->i_flags & EXT4_INLINE_DATA_FL) != 0;
282 }
283
284 /*
285 * Extent data and inline data are swapped on access, not here
286 */
287 if (!has_extents && !has_inline_data && (!islnk || !fast_symlink)) {
288 for (i = 0; i < EXT2_N_BLOCKS; i++)
289 t->i_block[i] = ext2fs_swab32(f->i_block[i]);
290 } else if (t != f) {
291 for (i = 0; i < EXT2_N_BLOCKS; i++)
292 t->i_block[i] = f->i_block[i];
293 }
294 t->i_generation = ext2fs_swab32(f->i_generation);
295 t->i_faddr = ext2fs_swab32(f->i_faddr);
296
297 switch (fs->super->s_creator_os) {
298 case EXT2_OS_LINUX:
299 t->osd1.linux1.l_i_version =
300 ext2fs_swab32(f->osd1.linux1.l_i_version);
301 t->osd2.linux2.l_i_blocks_hi =
302 ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
303 t->osd2.linux2.l_i_file_acl_high =
304 ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
305 t->osd2.linux2.l_i_uid_high =
306 ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
307 t->osd2.linux2.l_i_gid_high =
308 ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
309 t->osd2.linux2.l_i_checksum_lo =
310 ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
311 break;
312 case EXT2_OS_HURD:
313 t->osd1.hurd1.h_i_translator =
314 ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
315 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
316 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
317 t->osd2.hurd2.h_i_mode_high =
318 ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
319 t->osd2.hurd2.h_i_uid_high =
320 ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
321 t->osd2.hurd2.h_i_gid_high =
322 ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
323 t->osd2.hurd2.h_i_author =
324 ext2fs_swab32 (f->osd2.hurd2.h_i_author);
325 break;
326 default:
327 break;
328 }
329
330 if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
331 return; /* no i_extra_isize field */
332
333 if (hostorder)
334 extra_isize = f->i_extra_isize;
335 t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
336 if (!hostorder)
337 extra_isize = t->i_extra_isize;
338 if (extra_isize > EXT2_INODE_SIZE(fs->super) -
339 sizeof(struct ext2_inode)) {
340 /* this is error case: i_extra_size is too large */
341 return;
342 }
343 if (extra_isize & 3)
344 return; /* Illegal inode extra_isize */
345
346 inode_size = EXT2_GOOD_OLD_INODE_SIZE + extra_isize;
347 if (inode_includes(inode_size, i_checksum_hi))
348 t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
349 if (inode_includes(inode_size, i_ctime_extra))
350 t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
351 if (inode_includes(inode_size, i_mtime_extra))
352 t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
353 if (inode_includes(inode_size, i_atime_extra))
354 t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
355 if (inode_includes(inode_size, i_crtime))
356 t->i_crtime = ext2fs_swab32(f->i_crtime);
357 if (inode_includes(inode_size, i_crtime_extra))
358 t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
359 if (inode_includes(inode_size, i_version_hi))
360 t->i_version_hi = ext2fs_swab32(f->i_version_hi);
361 if (inode_includes(inode_size, i_projid))
362 t->i_projid = ext2fs_swab32(f->i_projid);
363 /* catch new static fields added after i_projid */
364 EXT2FS_BUILD_BUG_ON(sizeof(struct ext2_inode_large) != 160);
365
366 i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
367 if (bufsize < (int) i)
368 return; /* no space for EA magic */
369
370 eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
371 extra_isize);
372
373 attr_magic = *eaf;
374 if (!hostorder)
375 attr_magic = ext2fs_swab32(attr_magic);
376
377 if (attr_magic != EXT2_EXT_ATTR_MAGIC)
378 return; /* it seems no magic here */
379
380 eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
381 extra_isize);
382 *eat = ext2fs_swab32(*eaf);
383
384 /* convert EA(s) */
385 ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
386 bufsize - sizeof(struct ext2_inode) -
387 extra_isize - sizeof(__u32), 0);
388
389 }
390
ext2fs_swap_inode(ext2_filsys fs,struct ext2_inode * t,struct ext2_inode * f,int hostorder)391 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
392 struct ext2_inode *f, int hostorder)
393 {
394 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
395 (struct ext2_inode_large *) f, hostorder,
396 sizeof(struct ext2_inode));
397 }
398
ext2fs_swap_mmp(struct mmp_struct * mmp)399 void ext2fs_swap_mmp(struct mmp_struct *mmp)
400 {
401 mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
402 mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
403 mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
404 mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
405 mmp->mmp_checksum = ext2fs_swab32(mmp->mmp_checksum);
406 }
407
ext2fs_dirent_swab_in(ext2_filsys fs,char * buf,int flags)408 errcode_t ext2fs_dirent_swab_in(ext2_filsys fs, char *buf, int flags)
409 {
410 return ext2fs_dirent_swab_in2(fs, buf, fs->blocksize, flags);
411 }
412
ext2fs_dirent_swab_in2(ext2_filsys fs,char * buf,size_t size,int flags)413 errcode_t ext2fs_dirent_swab_in2(ext2_filsys fs, char *buf,
414 size_t size, int flags)
415 {
416 errcode_t retval;
417 char *p, *end;
418 struct ext2_dir_entry *dirent;
419 unsigned int name_len, rec_len, left;
420
421 p = (char *) buf;
422 end = (char *) buf + size;
423 left = size;
424 while (p < end-8) {
425 dirent = (struct ext2_dir_entry *) p;
426 dirent->inode = ext2fs_swab32(dirent->inode);
427 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
428 dirent->name_len = ext2fs_swab16(dirent->name_len);
429 name_len = dirent->name_len;
430 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
431 dirent->name_len = ext2fs_swab16(dirent->name_len);
432 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
433 if (retval)
434 return retval;
435 if ((rec_len < 8) || (rec_len % 4)) {
436 rec_len = 8;
437 retval = EXT2_ET_DIR_CORRUPTED;
438 } else if (((name_len & 0xFF) + 8) > rec_len)
439 retval = EXT2_ET_DIR_CORRUPTED;
440 if (rec_len > left)
441 return EXT2_ET_DIR_CORRUPTED;
442 left -= rec_len;
443 p += rec_len;
444 }
445
446 return 0;
447 }
448
ext2fs_dirent_swab_out(ext2_filsys fs,char * buf,int flags)449 errcode_t ext2fs_dirent_swab_out(ext2_filsys fs, char *buf, int flags)
450 {
451 return ext2fs_dirent_swab_out2(fs, buf, fs->blocksize, flags);
452 }
453
ext2fs_dirent_swab_out2(ext2_filsys fs,char * buf,size_t size,int flags)454 errcode_t ext2fs_dirent_swab_out2(ext2_filsys fs, char *buf,
455 size_t size, int flags)
456 {
457 errcode_t retval;
458 char *p, *end;
459 unsigned int rec_len;
460 struct ext2_dir_entry *dirent;
461
462 p = buf;
463 end = buf + size;
464 while (p < end) {
465 dirent = (struct ext2_dir_entry *) p;
466 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
467 if (retval)
468 return retval;
469 if ((rec_len < 8) ||
470 (rec_len % 4)) {
471 ext2fs_free_mem(&buf);
472 return EXT2_ET_DIR_CORRUPTED;
473 }
474 p += rec_len;
475 dirent->inode = ext2fs_swab32(dirent->inode);
476 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
477 dirent->name_len = ext2fs_swab16(dirent->name_len);
478 if (rec_len > size)
479 return EXT2_ET_DIR_CORRUPTED;
480 size -= rec_len;
481
482 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
483 dirent->name_len = ext2fs_swab16(dirent->name_len);
484 }
485
486 return 0;
487 }
488