From c929358e0292e7f0650b543f4085cd10d2624534 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sun, 23 Oct 2005 17:41:55 +0200 Subject: [PATCH] volume_id: check ext fs for valid blocksize, cause magic is only 2 bytes Signed-off-by: Kay Sievers --- extras/volume_id/volume_id/ext.c | 84 ++++++++++++++++++++++--------- extras/volume_id/volume_id/util.h | 2 + 2 files changed, 63 insertions(+), 23 deletions(-) diff --git a/extras/volume_id/volume_id/ext.c b/extras/volume_id/volume_id/ext.c index df2ebb696..7080f1dd3 100644 --- a/extras/volume_id/volume_id/ext.c +++ b/extras/volume_id/volume_id/ext.c @@ -29,31 +29,53 @@ #include "ext.h" struct ext2_super_block { - uint32_t inodes_count; - uint32_t blocks_count; - uint32_t r_blocks_count; - uint32_t free_blocks_count; - uint32_t free_inodes_count; - uint32_t first_data_block; - uint32_t log_block_size; - uint32_t dummy3[7]; - uint8_t magic[2]; - uint16_t state; - uint32_t dummy5[8]; - uint32_t feature_compat; - uint32_t feature_incompat; - uint32_t feature_ro_compat; - uint8_t uuid[16]; - uint8_t volume_name[16]; + 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); @@ -61,16 +83,32 @@ int volume_id_probe_ext(struct volume_id *id, uint64_t off) if (es == NULL) return -1; - if (es->magic[0] != 0123 || - es->magic[1] != 0357) + if (es->s_magic != cpu_to_le16(EXT_SUPER_MAGIC)) return -1; - volume_id_set_usage(id, VOLUME_ID_FILESYSTEM); - volume_id_set_label_raw(id, es->volume_name, 16); - volume_id_set_label_string(id, es->volume_name, 16); - volume_id_set_uuid(id, es->uuid, UUID_DCE); + bsize = 0x200 << 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; + } - if ((le32_to_cpu(es->feature_compat) & EXT3_FEATURE_COMPAT_HAS_JOURNAL) != 0) + 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"; diff --git a/extras/volume_id/volume_id/util.h b/extras/volume_id/volume_id/util.h index afaa0b7d8..6e16491c8 100644 --- a/extras/volume_id/volume_id/util.h +++ b/extras/volume_id/volume_id/util.h @@ -51,6 +51,7 @@ #define le64_to_cpu(x) (x) #define be16_to_cpu(x) bswap16(x) #define be32_to_cpu(x) bswap32(x) +#define cpu_to_le16(x) (x) #define cpu_to_le32(x) (x) #define cpu_to_be32(x) bswap32(x) #elif (__BYTE_ORDER == __BIG_ENDIAN) @@ -59,6 +60,7 @@ #define le64_to_cpu(x) bswap64(x) #define be16_to_cpu(x) (x) #define be32_to_cpu(x) (x) +#define cpu_to_le16(x) bswap16(x) #define cpu_to_le32(x) bswap32(x) #define cpu_to_be32(x) (x) #endif -- 2.30.2