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Diffstat (limited to 'libblkid/src/superblocks/minix.c')
| -rw-r--r-- | libblkid/src/superblocks/minix.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/libblkid/src/superblocks/minix.c b/libblkid/src/superblocks/minix.c new file mode 100644 index 000000000..9ea49fee8 --- /dev/null +++ b/libblkid/src/superblocks/minix.c @@ -0,0 +1,161 @@ +/* + * Copyright (C) 1999 by Andries Brouwer + * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o + * Copyright (C) 2001 by Andreas Dilger + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2008-2013 Karel Zak <kzak@redhat.com> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + */ + +#include <string.h> +#include "superblocks.h" +#include "minix.h" + +#define minix_swab16(doit, num) ((uint16_t) (doit ? swab16(num) : num)) +#define minix_swab32(doit, num) ((uint32_t) (doit ? swab32(num) : num)) + +static int get_minix_version(const unsigned char *data, int *other_endian) +{ + struct minix_super_block *sb = (struct minix_super_block *) data; + struct minix3_super_block *sb3 = (struct minix3_super_block *) data; + int version = 0; + + *other_endian = 0; + + switch (sb->s_magic) { + case MINIX_SUPER_MAGIC: + case MINIX_SUPER_MAGIC2: + version = 1; + break; + case MINIX2_SUPER_MAGIC: + case MINIX2_SUPER_MAGIC2: + version = 2; + break; + default: + if (sb3->s_magic == MINIX3_SUPER_MAGIC) + version = 3; + break; + } + + if (!version) { + *other_endian = 1; + + switch (swab16(sb->s_magic)) { + case MINIX_SUPER_MAGIC: + case MINIX_SUPER_MAGIC2: + version = 1; + break; + case MINIX2_SUPER_MAGIC: + case MINIX2_SUPER_MAGIC2: + version = 2; + break; + default: + if (sb3->s_magic == MINIX3_SUPER_MAGIC) + version = 3; + break; + } + } + if (!version) + return -1; + + DBG(LOWPROBE, ul_debug("minix version %d detected [%s]", version, +#if defined(WORDS_BIGENDIAN) + *other_endian ? "LE" : "BE" +#else + *other_endian ? "BE" : "LE" +#endif + )); + return version; +} + +static int probe_minix(blkid_probe pr, const struct blkid_idmag *mag) +{ + unsigned char *ext; + const unsigned char *data; + int version = 0, swabme = 0; + + data = blkid_probe_get_buffer(pr, 1024, + max(sizeof(struct minix_super_block), + sizeof(struct minix3_super_block))); + if (!data) + return errno ? -errno : 1; + version = get_minix_version(data, &swabme); + if (version < 1) + return 1; + + if (version <= 2) { + struct minix_super_block *sb = (struct minix_super_block *) data; + int zones, ninodes, imaps, zmaps, firstz; + + if (sb->s_imap_blocks == 0 || sb->s_zmap_blocks == 0) + return 1; + + zones = version == 2 ? minix_swab32(swabme, sb->s_zones) : + minix_swab16(swabme, sb->s_nzones); + ninodes = minix_swab16(swabme, sb->s_ninodes); + imaps = minix_swab16(swabme, sb->s_imap_blocks); + zmaps = minix_swab16(swabme, sb->s_zmap_blocks); + firstz = minix_swab16(swabme, sb->s_firstdatazone); + + /* sanity checks to be sure that the FS is really minix */ + if (imaps * MINIX_BLOCK_SIZE * 8 < ninodes + 1) + return 1; + if (zmaps * MINIX_BLOCK_SIZE * 8 < zones - firstz + 1) + return 1; + + } else if (version == 3) { + struct minix3_super_block *sb = (struct minix3_super_block *) data; + + if (sb->s_imap_blocks == 0 || sb->s_zmap_blocks == 0) + return 1; + } + + /* unfortunately, some parts of ext3 is sometimes possible to + * interpreted as minix superblock. So check for extN magic + * string. (For extN magic string and offsets see ext.c.) + */ + ext = blkid_probe_get_buffer(pr, 0x400 + 0x38, 2); + if (!ext) + return errno ? -errno : 1; + else if (memcmp(ext, "\123\357", 2) == 0) + return 1; + + blkid_probe_sprintf_version(pr, "%d", version); + return 0; +} + +const struct blkid_idinfo minix_idinfo = +{ + .name = "minix", + .usage = BLKID_USAGE_FILESYSTEM, + .probefunc = probe_minix, + .magics = + { + /* version 1 - LE */ + { .magic = "\177\023", .len = 2, .kboff = 1, .sboff = 0x10 }, + { .magic = "\217\023", .len = 2, .kboff = 1, .sboff = 0x10 }, + + /* version 1 - BE */ + { .magic = "\023\177", .len = 2, .kboff = 1, .sboff = 0x10 }, + { .magic = "\023\217", .len = 2, .kboff = 1, .sboff = 0x10 }, + + /* version 2 - LE */ + { .magic = "\150\044", .len = 2, .kboff = 1, .sboff = 0x10 }, + { .magic = "\170\044", .len = 2, .kboff = 1, .sboff = 0x10 }, + + /* version 2 - BE */ + { .magic = "\044\150", .len = 2, .kboff = 1, .sboff = 0x10 }, + { .magic = "\044\170", .len = 2, .kboff = 1, .sboff = 0x10 }, + + /* version 3 - LE */ + { .magic = "\132\115", .len = 2, .kboff = 1, .sboff = 0x18 }, + + /* version 3 - BE */ + { .magic = "\115\132", .len = 2, .kboff = 1, .sboff = 0x18 }, + + { NULL } + } +}; + |