diff options
Diffstat (limited to 'extras/volume_id/libvolume_id/ext.c')
| -rw-r--r-- | extras/volume_id/libvolume_id/ext.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/extras/volume_id/libvolume_id/ext.c b/extras/volume_id/libvolume_id/ext.c new file mode 100644 index 0000000000..d1f62dfb6f --- /dev/null +++ b/extras/volume_id/libvolume_id/ext.c @@ -0,0 +1,116 @@ +/* + * volume_id - reads filesystem label and uuid + * + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation version 2 of the License. + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE 1 +#endif + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <ctype.h> + +#include "volume_id.h" +#include "util.h" +#include "logging.h" + +struct ext2_super_block { + uint32_t s_inodes_count; + uint32_t s_blocks_count; + uint32_t s_r_blocks_count; + uint32_t s_free_blocks_count; + uint32_t s_free_inodes_count; + uint32_t s_first_data_block; + uint32_t s_log_block_size; + uint32_t s_log_frag_size; + uint32_t s_blocks_per_group; + uint32_t s_frags_per_group; + uint32_t s_inodes_per_group; + uint32_t s_mtime; + uint32_t s_wtime; + uint16_t s_mnt_count; + uint16_t s_max_mnt_count; + uint16_t s_magic; + uint16_t s_state; + uint16_t s_errors; + uint16_t s_minor_rev_level; + uint32_t s_lastcheck; + uint32_t s_checkinterval; + uint32_t s_creator_os; + uint32_t s_rev_level; + uint16_t s_def_resuid; + uint16_t s_def_resgid; + uint32_t s_first_ino; + uint16_t s_inode_size; + uint16_t s_block_group_nr; + uint32_t s_feature_compat; + uint32_t s_feature_incompat; + uint32_t s_feature_ro_compat; + uint8_t s_uuid[16]; + uint8_t s_volume_name[16]; +} __attribute__((__packed__)); + +#define EXT_SUPER_MAGIC 0xEF53 +#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x00000004 +#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x00000008 +#define EXT_SUPERBLOCK_OFFSET 0x400 + +#define EXT3_MIN_BLOCK_SIZE 0x400 +#define EXT3_MAX_BLOCK_SIZE 0x1000 + +int volume_id_probe_ext(struct volume_id *id, uint64_t off) +{ + struct ext2_super_block *es; + size_t bsize; + + dbg("probing at offset 0x%llx", (unsigned long long) off); + + es = (struct ext2_super_block *) volume_id_get_buffer(id, off + EXT_SUPERBLOCK_OFFSET, 0x200); + if (es == NULL) + return -1; + + if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC)) + return -1; + + bsize = 0x400 << le32_to_cpu(es->s_log_block_size); + dbg("ext blocksize 0x%zx", bsize); + if (bsize < EXT3_MIN_BLOCK_SIZE || bsize > EXT3_MAX_BLOCK_SIZE) { + dbg("invalid ext blocksize"); + return -1; + } + + volume_id_set_label_raw(id, es->s_volume_name, 16); + volume_id_set_label_string(id, es->s_volume_name, 16); + volume_id_set_uuid(id, es->s_uuid, UUID_DCE); + snprintf(id->type_version, sizeof(id->type_version)-1, + "%u.%u", es->s_rev_level, es->s_minor_rev_level); + + /* check for external journal device */ + if ((le32_to_cpu(es->s_feature_incompat) & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) != 0) { + volume_id_set_usage(id, VOLUME_ID_OTHER); + id->type = "jbd"; + return 0; + } + + /* check for ext2 / ext3 */ + volume_id_set_usage(id, VOLUME_ID_FILESYSTEM); + if ((le32_to_cpu(es->s_feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) + id->type = "ext3"; + else + id->type = "ext2"; + + return 0; +} |