1 /*        $NetBSD: ext2fs_bswap.c,v 1.25 2023/08/26 05:22:50 riastradh 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 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: ext2fs_bswap.c,v 1.25 2023/08/26 05:22:50 riastradh Exp $");
30 
31 #include <sys/types.h>
32 #include <ufs/ext2fs/ext2fs.h>
33 #include <ufs/ext2fs/ext2fs_dinode.h>
34 
35 #if defined(_KERNEL)
36 #include <sys/systm.h>
37 #else
38 #include <string.h>
39 #endif
40 
41 /* These functions are only needed if native byte order is not little endian */
42 #if BYTE_ORDER == BIG_ENDIAN
43 void
e2fs_sb_bswap(struct ext2fs * old,struct ext2fs * new)44 e2fs_sb_bswap(struct ext2fs *old, struct ext2fs *new)
45 {
46 
47           /* preserve unused fields */
48           memcpy(new, old, sizeof(struct ext2fs));
49           new->e2fs_icount    =         bswap32(old->e2fs_icount);
50           new->e2fs_bcount    =         bswap32(old->e2fs_bcount);
51           new->e2fs_rbcount   =         bswap32(old->e2fs_rbcount);
52           new->e2fs_fbcount   =         bswap32(old->e2fs_fbcount);
53           new->e2fs_ficount   =         bswap32(old->e2fs_ficount);
54           new->e2fs_first_dblock        =         bswap32(old->e2fs_first_dblock);
55           new->e2fs_log_bsize =         bswap32(old->e2fs_log_bsize);
56           new->e2fs_fsize               =         bswap32(old->e2fs_fsize);
57           new->e2fs_bpg                 =         bswap32(old->e2fs_bpg);
58           new->e2fs_fpg                 =         bswap32(old->e2fs_fpg);
59           new->e2fs_ipg                 =         bswap32(old->e2fs_ipg);
60           new->e2fs_mtime               =         bswap32(old->e2fs_mtime);
61           new->e2fs_wtime               =         bswap32(old->e2fs_wtime);
62           new->e2fs_mnt_count =         bswap16(old->e2fs_mnt_count);
63           new->e2fs_max_mnt_count       =         bswap16(old->e2fs_max_mnt_count);
64           new->e2fs_magic               =         bswap16(old->e2fs_magic);
65           new->e2fs_state               =         bswap16(old->e2fs_state);
66           new->e2fs_beh                 =         bswap16(old->e2fs_beh);
67           new->e2fs_minrev    =         bswap16(old->e2fs_minrev);
68           new->e2fs_lastfsck  =         bswap32(old->e2fs_lastfsck);
69           new->e2fs_fsckintv  =         bswap32(old->e2fs_fsckintv);
70           new->e2fs_creator   =         bswap32(old->e2fs_creator);
71           new->e2fs_rev                 =         bswap32(old->e2fs_rev);
72           new->e2fs_ruid                =         bswap16(old->e2fs_ruid);
73           new->e2fs_rgid                =         bswap16(old->e2fs_rgid);
74           new->e2fs_first_ino =         bswap32(old->e2fs_first_ino);
75           new->e2fs_inode_size          =         bswap16(old->e2fs_inode_size);
76           new->e2fs_block_group_nr =    bswap16(old->e2fs_block_group_nr);
77           new->e2fs_features_compat =   bswap32(old->e2fs_features_compat);
78           new->e2fs_features_incompat = bswap32(old->e2fs_features_incompat);
79           new->e2fs_features_rocompat = bswap32(old->e2fs_features_rocompat);
80           new->e2fs_algo                =         bswap32(old->e2fs_algo);
81           new->e2fs_reserved_ngdb       =         bswap16(old->e2fs_reserved_ngdb);
82           new->e4fs_want_extra_isize =  bswap16(old->e4fs_want_extra_isize);
83 }
84 
85 void
e2fs_i_bswap(struct ext2fs_dinode * old,struct ext2fs_dinode * new,size_t isize)86 e2fs_i_bswap(struct ext2fs_dinode *old, struct ext2fs_dinode *new, size_t isize)
87 {
88           /* preserve non-swapped and unused fields */
89           memcpy(new, old, isize);
90 
91           /* swap what needs to be swapped */
92           new->e2di_mode                =         bswap16(old->e2di_mode);
93           new->e2di_uid                 =         bswap16(old->e2di_uid);
94           new->e2di_gid                 =         bswap16(old->e2di_gid);
95           new->e2di_nlink               =         bswap16(old->e2di_nlink);
96           new->e2di_size                =         bswap32(old->e2di_size);
97           new->e2di_atime               =         bswap32(old->e2di_atime);
98           new->e2di_ctime               =         bswap32(old->e2di_ctime);
99           new->e2di_mtime               =         bswap32(old->e2di_mtime);
100           new->e2di_dtime               =         bswap32(old->e2di_dtime);
101           new->e2di_nblock    =         bswap32(old->e2di_nblock);
102           new->e2di_flags               =         bswap32(old->e2di_flags);
103           new->e2di_version   =         bswap32(old->e2di_version);
104           new->e2di_gen                 =         bswap32(old->e2di_gen);
105           new->e2di_facl                =         bswap32(old->e2di_facl);
106           new->e2di_size_high =         bswap32(old->e2di_size_high);
107           new->e2di_nblock_high         =         bswap16(old->e2di_nblock_high);
108           new->e2di_facl_high =         bswap16(old->e2di_facl_high);
109           new->e2di_uid_high  =         bswap16(old->e2di_uid_high);
110           new->e2di_gid_high  =         bswap16(old->e2di_gid_high);
111           new->e2di_checksum_low  =     bswap16(old->e2di_checksum_low);
112 
113           /*
114            * Following fields are only supported for inode sizes bigger
115            * than the old ext2 one
116            */
117           if (isize == EXT2_REV0_DINODE_SIZE)
118                     return;
119 
120           new->e2di_extra_isize   = bswap16(old->e2di_extra_isize);
121           new->e2di_checksum_high = bswap16(old->e2di_checksum_high);
122 
123           /* Following fields are ext4, might not be actually present */
124           if (EXT2_DINODE_FITS(new, e2di_ctime_extra, isize))
125                     new->e2di_ctime_extra   = bswap32(old->e2di_ctime_extra);
126           if (EXT2_DINODE_FITS(new, e2di_mtime_extra, isize))
127                     new->e2di_mtime_extra         = bswap32(old->e2di_mtime_extra);
128           if (EXT2_DINODE_FITS(new, e2di_atime_extra, isize))
129                     new->e2di_atime_extra         = bswap32(old->e2di_atime_extra);
130           if (EXT2_DINODE_FITS(new, e2di_crtime, isize))
131                     new->e2di_crtime    = bswap32(old->e2di_crtime);
132           if (EXT2_DINODE_FITS(new, e2di_crtime_extra, isize))
133                     new->e2di_crtime_extra        = bswap32(old->e2di_crtime_extra);
134           if (EXT2_DINODE_FITS(new, e2di_version_high, isize))
135                     new->e2di_version_high        = bswap32(old->e2di_version_high);
136           if (EXT2_DINODE_FITS(new, e2di_projid, isize))
137                     new->e2di_projid    = bswap32(old->e2di_projid);
138 }
139 #endif
140