swapfs.c revision b7c5b4030870b31d73019d9d9ec55d550772590b
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 Public
8 * License.
9 * %End-Header%
10 */
11
12#include <stdio.h>
13#if HAVE_UNISTD_H
14#include <unistd.h>
15#endif
16#include <string.h>
17#include <time.h>
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21#include <ext2fs/ext2_ext_attr.h>
22
23#ifdef WORDS_BIGENDIAN
24void ext2fs_swap_super(struct ext2_super_block * sb)
25{
26  	int i;
27	sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
28	sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
29	sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
30	sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
31	sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
32	sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
33	sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
34	sb->s_log_frag_size = ext2fs_swab32(sb->s_log_frag_size);
35	sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
36	sb->s_frags_per_group = ext2fs_swab32(sb->s_frags_per_group);
37	sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
38	sb->s_mtime = ext2fs_swab32(sb->s_mtime);
39	sb->s_wtime = ext2fs_swab32(sb->s_wtime);
40	sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
41	sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
42	sb->s_magic = ext2fs_swab16(sb->s_magic);
43	sb->s_state = ext2fs_swab16(sb->s_state);
44	sb->s_errors = ext2fs_swab16(sb->s_errors);
45	sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
46	sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
47	sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
48	sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
49	sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
50	sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
51	sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
52	sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
53	sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
54	sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
55	sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
56	sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
57	sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
58	sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
59	sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
60	sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
61	sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
62	sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
63	sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
64	sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
65	sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
66	sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
67	sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
68	sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
69	sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
70	sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
71	sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
72	sb->s_flags = ext2fs_swab32(sb->s_flags);
73	sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
74	for (i=0; i < 4; i++)
75		sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
76	for (i=0; i < 17; i++)
77		sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
78
79}
80
81void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
82{
83	gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
84	gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
85	gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
86	gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
87	gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
88	gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
89	gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
90	gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
91	gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
92}
93
94void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
95				 struct ext2_ext_attr_header *from_header)
96{
97	int n;
98
99	to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
100	to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
101	to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
102	to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
103	for (n = 0; n < 4; n++)
104		to_header->h_reserved[n] =
105			ext2fs_swab32(from_header->h_reserved[n]);
106}
107
108void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
109				struct ext2_ext_attr_entry *from_entry)
110{
111	to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
112	to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
113	to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
114	to_entry->e_hash	= ext2fs_swab32(from_entry->e_hash);
115}
116
117void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
118{
119	struct ext2_ext_attr_header *from_header =
120		(struct ext2_ext_attr_header *)from;
121	struct ext2_ext_attr_header *to_header =
122		(struct ext2_ext_attr_header *)to;
123	struct ext2_ext_attr_entry *from_entry, *to_entry;
124	char *from_end = (char *)from_header + bufsize;
125
126	if (to_header != from_header)
127		memcpy(to_header, from_header, bufsize);
128
129	if (has_header) {
130		ext2fs_swap_ext_attr_header(to_header, from_header);
131
132		from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
133		to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
134	} else {
135		from_entry = (struct ext2_ext_attr_entry *)from_header;
136		to_entry   = (struct ext2_ext_attr_entry *)to_header;
137	}
138
139	while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
140		ext2fs_swap_ext_attr_entry(to_entry, from_entry);
141		from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
142		to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
143	}
144}
145
146void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
147			    struct ext2_inode_large *f, int hostorder,
148			    int bufsize)
149{
150	unsigned i, has_data_blocks, extra_isize, attr_magic;
151	int has_extents = 0;
152	int islnk = 0;
153	__u32 *eaf, *eat;
154
155	if (hostorder && LINUX_S_ISLNK(f->i_mode))
156		islnk = 1;
157	t->i_mode = ext2fs_swab16(f->i_mode);
158	if (!hostorder && LINUX_S_ISLNK(t->i_mode))
159		islnk = 1;
160	t->i_uid = ext2fs_swab16(f->i_uid);
161	t->i_size = ext2fs_swab32(f->i_size);
162	t->i_atime = ext2fs_swab32(f->i_atime);
163	t->i_ctime = ext2fs_swab32(f->i_ctime);
164	t->i_mtime = ext2fs_swab32(f->i_mtime);
165	t->i_dtime = ext2fs_swab32(f->i_dtime);
166	t->i_gid = ext2fs_swab16(f->i_gid);
167	t->i_links_count = ext2fs_swab16(f->i_links_count);
168	t->i_file_acl = ext2fs_swab32(f->i_file_acl);
169	if (hostorder)
170		has_data_blocks = ext2fs_inode_data_blocks(fs,
171					   (struct ext2_inode *) f);
172	t->i_blocks = ext2fs_swab32(f->i_blocks);
173	if (!hostorder)
174		has_data_blocks = ext2fs_inode_data_blocks(fs,
175					   (struct ext2_inode *) t);
176	if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
177		has_extents = 1;
178	t->i_flags = ext2fs_swab32(f->i_flags);
179	if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
180		has_extents = 1;
181	t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
182	/* extent data are swapped on access, not here */
183	if (!has_extents && (!islnk || has_data_blocks)) {
184		for (i = 0; i < EXT2_N_BLOCKS; i++)
185			t->i_block[i] = ext2fs_swab32(f->i_block[i]);
186	} else if (t != f) {
187		for (i = 0; i < EXT2_N_BLOCKS; i++)
188			t->i_block[i] = f->i_block[i];
189	}
190	t->i_generation = ext2fs_swab32(f->i_generation);
191	t->i_faddr = ext2fs_swab32(f->i_faddr);
192
193	switch (fs->super->s_creator_os) {
194	case EXT2_OS_LINUX:
195		t->osd1.linux1.l_i_version =
196			ext2fs_swab32(f->osd1.linux1.l_i_version);
197		t->osd2.linux2.l_i_blocks_hi =
198			ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
199		t->osd2.linux2.l_i_file_acl_high =
200			ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
201		t->osd2.linux2.l_i_uid_high =
202		  ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
203		t->osd2.linux2.l_i_gid_high =
204		  ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
205		t->osd2.linux2.l_i_reserved2 =
206			ext2fs_swab32(f->osd2.linux2.l_i_reserved2);
207		break;
208	case EXT2_OS_HURD:
209		t->osd1.hurd1.h_i_translator =
210		  ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
211		t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
212		t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
213		t->osd2.hurd2.h_i_mode_high =
214		  ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
215		t->osd2.hurd2.h_i_uid_high =
216		  ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
217		t->osd2.hurd2.h_i_gid_high =
218		  ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
219		t->osd2.hurd2.h_i_author =
220		  ext2fs_swab32 (f->osd2.hurd2.h_i_author);
221		break;
222	default:
223		break;
224	}
225
226	if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
227		return; /* no i_extra_isize field */
228
229	if (hostorder)
230		extra_isize = f->i_extra_isize;
231	t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
232	if (!hostorder)
233		extra_isize = t->i_extra_isize;
234	if (extra_isize > EXT2_INODE_SIZE(fs->super) -
235				sizeof(struct ext2_inode)) {
236		/* this is error case: i_extra_size is too large */
237		return;
238	}
239
240	i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
241	if (bufsize < (int) i)
242		return; /* no space for EA magic */
243
244	eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
245					extra_isize);
246
247	attr_magic = *eaf;
248	if (!hostorder)
249		attr_magic = ext2fs_swab32(attr_magic);
250
251	if (attr_magic != EXT2_EXT_ATTR_MAGIC)
252		return; /* it seems no magic here */
253
254	eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
255					extra_isize);
256	*eat = ext2fs_swab32(*eaf);
257
258	/* convert EA(s) */
259	ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
260			     bufsize - sizeof(struct ext2_inode) -
261			     extra_isize - sizeof(__u32), 0);
262
263}
264
265void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
266		       struct ext2_inode *f, int hostorder)
267{
268	ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
269				(struct ext2_inode_large *) f, hostorder,
270				sizeof(struct ext2_inode));
271}
272
273#endif
274