| /* |
| * by rmk |
| * |
| * Detect filesystem type (on stdin) and output strings for two |
| * environment variables: |
| * FSTYPE - filesystem type |
| * FSSIZE - filesystem size (if known) |
| * |
| * We currently detect the filesystems listed below in the struct |
| * "imagetype images" (in the order they are listed). |
| */ |
| |
| #include <sys/types.h> |
| #include <stdio.h> |
| #include <ctype.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <endian.h> |
| #include <netinet/in.h> |
| #include <sys/utsname.h> |
| #include <sys/vfs.h> |
| |
| #define cpu_to_be32(x) __cpu_to_be32(x) /* Needed by romfs_fs.h */ |
| |
| #include "btrfs.h" |
| #include "cramfs_fs.h" |
| #include "ext2_fs.h" |
| #include "ext3_fs.h" |
| #include "gfs2_fs.h" |
| #include "iso9660_sb.h" |
| #include "luks_fs.h" |
| #include "lvm2_sb.h" |
| #include "minix_fs.h" |
| #include "nilfs_fs.h" |
| #include "ocfs2_fs.h" |
| #include "romfs_fs.h" |
| #include "squashfs_fs.h" |
| #include "xfs_sb.h" |
| |
| /* |
| * Slightly cleaned up version of jfs_superblock to |
| * avoid pulling in other kernel header files. |
| */ |
| #include "jfs_superblock.h" |
| |
| /* |
| * reiserfs_fs.h is too sick to include directly. |
| * Use a cleaned up version. |
| */ |
| #include "reiserfs_fs.h" |
| #include "reiser4_fs.h" |
| |
| #include "fstype.h" |
| |
| #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0])) |
| |
| #define BLOCK_SIZE 1024 |
| |
| /* Swap needs the definition of block size */ |
| #include "swap_fs.h" |
| |
| static int gzip_image(const void *buf, unsigned long long *bytes) |
| { |
| const unsigned char *p = buf; |
| |
| if (p[0] == 037 && (p[1] == 0213 || p[1] == 0236)) { |
| /* The length of a gzip stream can only be determined |
| by processing the whole stream */ |
| *bytes = 0ULL; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int cramfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct cramfs_super *sb = (const struct cramfs_super *)buf; |
| |
| if (sb->magic == CRAMFS_MAGIC) { |
| if (sb->flags & CRAMFS_FLAG_FSID_VERSION_2) |
| *bytes = (unsigned long long)sb->fsid.blocks << 10; |
| else |
| *bytes = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int romfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct romfs_super_block *sb = |
| (const struct romfs_super_block *)buf; |
| |
| if (sb->word0 == ROMSB_WORD0 && sb->word1 == ROMSB_WORD1) { |
| *bytes = __be32_to_cpu(sb->size); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int minix_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct minix_super_block *sb = |
| (const struct minix_super_block *)buf; |
| |
| if (sb->s_magic == MINIX_SUPER_MAGIC || |
| sb->s_magic == MINIX_SUPER_MAGIC2) { |
| *bytes = (unsigned long long)sb->s_nzones |
| << (sb->s_log_zone_size + 10); |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* |
| * Check to see if a filesystem is in /proc/filesystems. |
| * Returns 1 if found, 0 if not |
| */ |
| static int fs_proc_check(const char *fs_name) |
| { |
| FILE *f; |
| char buf[80], *cp, *t; |
| |
| f = fopen("/proc/filesystems", "r"); |
| if (!f) |
| return 0; |
| while (fgets(buf, sizeof(buf), f)) { |
| cp = buf; |
| if (!isspace(*cp)) { |
| while (*cp && !isspace(*cp)) |
| cp++; |
| } |
| while (*cp && isspace(*cp)) |
| cp++; |
| t = strchr(cp, '\n'); |
| if (t != NULL) |
| *t = 0; |
| t = strchr(cp, '\t'); |
| if (t != NULL) |
| *t = 0; |
| t = strchr(cp, ' '); |
| if (t != NULL) |
| *t = 0; |
| if (!strcmp(fs_name, cp)) { |
| fclose(f); |
| return 1; |
| } |
| } |
| fclose(f); |
| return 0; |
| } |
| |
| /* |
| * Check to see if a filesystem is available as a module |
| * Returns 1 if found, 0 if not |
| */ |
| static int check_for_modules(const char *fs_name) |
| { |
| struct utsname uts; |
| FILE *f; |
| char buf[1024], *cp, *t; |
| int i; |
| |
| if (uname(&uts)) |
| return 0; |
| snprintf(buf, sizeof(buf), "/lib/modules/%s/modules.dep", uts.release); |
| |
| f = fopen(buf, "r"); |
| if (!f) |
| return 0; |
| while (fgets(buf, sizeof(buf), f)) { |
| cp = strchr(buf, ':'); |
| if (cp == NULL) |
| continue; |
| *cp = 0; |
| cp = strrchr(buf, '/'); |
| if (cp == NULL) |
| continue; |
| cp++; |
| i = strlen(cp); |
| if (i > 3) { |
| t = cp + i - 3; |
| if (!strcmp(t, ".ko")) |
| *t = 0; |
| } |
| if (!strcmp(cp, fs_name)) { |
| fclose(f); |
| return 1; |
| } |
| } |
| fclose(f); |
| return 0; |
| } |
| |
| static int base_ext4_image(const void *buf, unsigned long long *bytes, |
| int *test_fs) |
| { |
| const struct ext3_super_block *sb = |
| (const struct ext3_super_block *)buf; |
| |
| if (sb->s_magic != __cpu_to_le16(EXT2_SUPER_MAGIC)) |
| return 0; |
| |
| /* There is at least one feature not supported by ext3 */ |
| if ((sb->s_feature_incompat |
| & __cpu_to_le32(EXT3_FEATURE_INCOMPAT_UNSUPPORTED)) || |
| (sb->s_feature_ro_compat |
| & __cpu_to_le32(EXT3_FEATURE_RO_COMPAT_UNSUPPORTED))) { |
| *bytes = (unsigned long long)__le32_to_cpu(sb->s_blocks_count) |
| << (10 + __le32_to_cpu(sb->s_log_block_size)); |
| *test_fs = (sb->s_flags & |
| __cpu_to_le32(EXT2_FLAGS_TEST_FILESYS)) != 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int ext4_image(const void *buf, unsigned long long *bytes) |
| { |
| int ret, test_fs, ext4dev_present, ext4_present; |
| |
| ret = base_ext4_image(buf, bytes, &test_fs); |
| if (ret == 0) |
| return 0; |
| ext4dev_present = (fs_proc_check("ext4dev") || |
| check_for_modules("ext4dev")); |
| ext4_present = (fs_proc_check("ext4") || check_for_modules("ext4")); |
| if ((test_fs || !ext4_present) && ext4dev_present) |
| return 0; |
| return 1; |
| } |
| |
| static int ext4dev_image(const void *buf, unsigned long long *bytes) |
| { |
| int ret, test_fs, ext4dev_present, ext4_present; |
| |
| ret = base_ext4_image(buf, bytes, &test_fs); |
| if (ret == 0) |
| return 0; |
| ext4dev_present = (fs_proc_check("ext4dev") || |
| check_for_modules("ext4dev")); |
| ext4_present = (fs_proc_check("ext4") || check_for_modules("ext4")); |
| if ((!test_fs || !ext4dev_present) && ext4_present) |
| return 0; |
| return 1; |
| } |
| |
| static int ext3_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct ext3_super_block *sb = |
| (const struct ext3_super_block *)buf; |
| |
| if (sb->s_magic == __cpu_to_le16(EXT2_SUPER_MAGIC) && |
| sb-> |
| s_feature_compat & __cpu_to_le32(EXT3_FEATURE_COMPAT_HAS_JOURNAL)) { |
| *bytes = (unsigned long long)__le32_to_cpu(sb->s_blocks_count) |
| << (10 + __le32_to_cpu(sb->s_log_block_size)); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int ext2_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct ext2_super_block *sb = |
| (const struct ext2_super_block *)buf; |
| |
| if (sb->s_magic == __cpu_to_le16(EXT2_SUPER_MAGIC)) { |
| *bytes = (unsigned long long)__le32_to_cpu(sb->s_blocks_count) |
| << (10 + __le32_to_cpu(sb->s_log_block_size)); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int reiserfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct reiserfs_super_block *sb = |
| (const struct reiserfs_super_block *)buf; |
| |
| if (memcmp(REISERFS_MAGIC(sb), REISERFS_SUPER_MAGIC_STRING, |
| sizeof(REISERFS_SUPER_MAGIC_STRING) - 1) == 0 || |
| memcmp(REISERFS_MAGIC(sb), REISER2FS_SUPER_MAGIC_STRING, |
| sizeof(REISER2FS_SUPER_MAGIC_STRING) - 1) == 0 || |
| memcmp(REISERFS_MAGIC(sb), REISER2FS_JR_SUPER_MAGIC_STRING, |
| sizeof(REISER2FS_JR_SUPER_MAGIC_STRING) - 1) == 0) { |
| *bytes = (unsigned long long)REISERFS_BLOCK_COUNT(sb) * |
| REISERFS_BLOCKSIZE(sb); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int reiser4_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct reiser4_master_sb *sb = |
| (const struct reiser4_master_sb *)buf; |
| |
| if (memcmp(sb->ms_magic, REISER4_SUPER_MAGIC_STRING, |
| sizeof(REISER4_SUPER_MAGIC_STRING) - 1) == 0) { |
| *bytes = (unsigned long long) __le32_to_cpu(sb->ms_format) * |
| __le32_to_cpu(sb->ms_blksize); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int xfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct xfs_sb *sb = (const struct xfs_sb *)buf; |
| |
| if (__be32_to_cpu(sb->sb_magicnum) == XFS_SB_MAGIC) { |
| *bytes = __be64_to_cpu(sb->sb_dblocks) * |
| __be32_to_cpu(sb->sb_blocksize); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int jfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct jfs_superblock *sb = (const struct jfs_superblock *)buf; |
| |
| if (!memcmp(sb->s_magic, JFS_MAGIC, 4)) { |
| *bytes = __le64_to_cpu(sb->s_size) |
| << __le16_to_cpu(sb->s_l2pbsize); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int luks_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct luks_partition_header *lph = |
| (const struct luks_partition_header *)buf; |
| |
| if (!memcmp(lph->magic, LUKS_MAGIC, LUKS_MAGIC_L)) { |
| /* FSSIZE is dictated by the underlying fs, not by LUKS */ |
| *blocks = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int swap_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct swap_super_block *ssb = |
| (const struct swap_super_block *)buf; |
| |
| if (!memcmp(ssb->magic, SWAP_MAGIC_1, SWAP_MAGIC_L) || |
| !memcmp(ssb->magic, SWAP_MAGIC_2, SWAP_MAGIC_L)) { |
| *blocks = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int suspend_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct swap_super_block *ssb = |
| (const struct swap_super_block *)buf; |
| |
| if (!memcmp(ssb->magic, SUSP_MAGIC_1, SUSP_MAGIC_L) || |
| !memcmp(ssb->magic, SUSP_MAGIC_2, SUSP_MAGIC_L) || |
| !memcmp(ssb->magic, SUSP_MAGIC_U, SUSP_MAGIC_L)) { |
| *blocks = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int lvm2_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct lvm2_super_block *lsb; |
| int i; |
| |
| /* We must check every 512 byte sector */ |
| for (i = 0; i < BLOCK_SIZE; i += 0x200) { |
| lsb = (const struct lvm2_super_block *)(buf + i); |
| |
| if (!memcmp(lsb->magic, LVM2_MAGIC, LVM2_MAGIC_L) && |
| !memcmp(lsb->type, LVM2_TYPE, LVM2_TYPE_L)) { |
| /* This is just one of possibly many PV's */ |
| *blocks = 0; |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int iso_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct iso_volume_descriptor *isovd = |
| (const struct iso_volume_descriptor *)buf; |
| const struct iso_hs_volume_descriptor *isohsvd = |
| (const struct iso_hs_volume_descriptor *)buf; |
| |
| if (!memcmp(isovd->id, ISO_MAGIC, ISO_MAGIC_L) || |
| !memcmp(isohsvd->id, ISO_HS_MAGIC, ISO_HS_MAGIC_L)) { |
| *blocks = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int squashfs_image(const void *buf, unsigned long long *blocks) |
| { |
| const struct squashfs_super_block *sb = |
| (const struct squashfs_super_block *)buf; |
| |
| if (sb->s_magic == SQUASHFS_MAGIC |
| || sb->s_magic == SQUASHFS_MAGIC_SWAP |
| || sb->s_magic == SQUASHFS_MAGIC_LZMA |
| || sb->s_magic == SQUASHFS_MAGIC_LZMA_SWAP) { |
| *blocks = (unsigned long long) sb->bytes_used; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int gfs2_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct gfs2_sb *sb = |
| (const struct gfs2_sb *)buf; |
| |
| if (__be32_to_cpu(sb->sb_header.mh_magic) == GFS2_MAGIC |
| && (__be32_to_cpu(sb->sb_fs_format) == GFS2_FORMAT_FS |
| || __be32_to_cpu(sb->sb_fs_format) == GFS2_FORMAT_MULTI)) { |
| *bytes = 0; /* cpu_to_be32(sb->sb_bsize) * ?; */ |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int ocfs2_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct ocfs2_dinode *sb = |
| (const struct ocfs2_dinode *)buf; |
| |
| if (!memcmp(sb->i_signature, OCFS2_SUPER_BLOCK_SIGNATURE, |
| sizeof(OCFS2_SUPER_BLOCK_SIGNATURE) - 1)) { |
| *bytes = 0; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int nilfs2_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct nilfs_super_block *sb = |
| (const struct nilfs_super_block *)buf; |
| |
| if (sb->s_magic == __cpu_to_le16(NILFS_SUPER_MAGIC) && |
| sb->s_rev_level == __cpu_to_le32(2)) { |
| *bytes = (unsigned long long)__le64_to_cpu(sb->s_dev_size); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int btrfs_image(const void *buf, unsigned long long *bytes) |
| { |
| const struct btrfs_super_block *sb = |
| (const struct btrfs_super_block *)buf; |
| |
| if (!memcmp(sb->magic, BTRFS_MAGIC, BTRFS_MAGIC_L)) { |
| *bytes = (unsigned long long)__le64_to_cpu(sb->total_bytes); |
| return 1; |
| } |
| return 0; |
| } |
| |
| struct imagetype { |
| off_t block; |
| const char name[12]; |
| int (*identify) (const void *, unsigned long long *); |
| }; |
| |
| /* |
| * Note: |
| * |
| * Minix test needs to come after ext3/ext2, since it's possible for |
| * ext3/ext2 to look like minix by pure random chance. |
| * |
| * LVM comes after all other filesystems since it's possible |
| * that an old lvm signature is left on the disk if pvremove |
| * is not used before creating the new fs. |
| * |
| * The same goes for LUKS as for LVM. |
| */ |
| static struct imagetype images[] = { |
| {0, "gzip", gzip_image}, |
| {0, "cramfs", cramfs_image}, |
| {0, "romfs", romfs_image}, |
| {0, "xfs", xfs_image}, |
| {0, "squashfs", squashfs_image}, |
| {1, "ext4dev", ext4dev_image}, |
| {1, "ext4", ext4_image}, |
| {1, "ext3", ext3_image}, |
| {1, "ext2", ext2_image}, |
| {1, "minix", minix_image}, |
| {1, "nilfs2", nilfs2_image}, |
| {2, "ocfs2", ocfs2_image}, |
| {8, "reiserfs", reiserfs_image}, |
| {64, "reiserfs", reiserfs_image}, |
| {64, "reiser4", reiser4_image}, |
| {64, "gfs2", gfs2_image}, |
| {64, "btrfs", btrfs_image}, |
| {32, "jfs", jfs_image}, |
| {32, "iso9660", iso_image}, |
| {0, "luks", luks_image}, |
| {0, "lvm2", lvm2_image}, |
| {1, "lvm2", lvm2_image}, |
| {-1, "swap", swap_image}, |
| {-1, "suspend", suspend_image}, |
| {0, "", NULL} |
| }; |
| |
| int identify_fs(int fd, const char **fstype, |
| unsigned long long *bytes, off_t offset) |
| { |
| uint64_t buf[BLOCK_SIZE >> 3]; /* 64-bit worst case alignment */ |
| off_t cur_block = (off_t) -1; |
| struct imagetype *ip; |
| int ret; |
| unsigned long long dummy; |
| |
| if (!bytes) |
| bytes = &dummy; |
| |
| *fstype = NULL; |
| *bytes = 0; |
| |
| for (ip = images; ip->identify; ip++) { |
| /* Hack for swap, which apparently is dependent on page size */ |
| if (ip->block == -1) |
| ip->block = SWAP_OFFSET(); |
| |
| if (cur_block != ip->block) { |
| /* |
| * Read block. |
| */ |
| cur_block = ip->block; |
| ret = pread(fd, buf, BLOCK_SIZE, |
| offset + cur_block * BLOCK_SIZE); |
| if (ret != BLOCK_SIZE) |
| return -1; /* error */ |
| } |
| |
| if (ip->identify(buf, bytes)) { |
| *fstype = ip->name; |
| return 0; |
| } |
| } |
| |
| return 1; /* Unknown filesystem */ |
| } |