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-rw-r--r--toys/mke2fs.c241
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diff --git a/toys/mke2fs.c b/toys/mke2fs.c
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+/* vi: set ts=4:
+ *
+ * mke2fs.c - Create an ext2 filesystem image.
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ */
+
+#include "toys.h"
+
+// Stuff defined in linux/ext2_fs.h
+
+#define EXT2_SUPER_MAGIC 0xEF53
+
+struct ext2_inode {
+ uint16_t mode; // File mode
+ uint16_t uid; // Low 16 bits of Owner Uid
+ uint32_t size; // Size in bytes
+ uint32_t atime; // Access time
+ uint32_t ctime; // Creation time
+ uint32_t mtime; // Modification time
+ uint32_t dtime; // Deletion Time
+ uint16_t gid; // Low 16 bits of Group Id
+ uint16_t links_count; // Links count
+ uint32_t blocks; // Blocks count
+ uint32_t flags; // File flags
+ uint32_t reserved1;
+ uint32_t block[15]; // Pointers to blocks
+ uint32_t generation; // File version (for NFS)
+ uint32_t file_acl; // File ACL
+ uint32_t dir_acl; // Directory ACL
+ uint32_t faddr; // Fragment address
+ uint8_t frag; // Fragment number
+ uint8_t fsize; // Fragment size
+ uint16_t pad1;
+ uint16_t uid_high; // High bits of uid
+ uint16_t gid_high; // High bits of gid
+ uint32_t reserved2;
+};
+
+struct ext2_super_block {
+ uint32_t inodes_count; // Inodes count
+ uint32_t blocks_count; // Blocks count
+ uint32_t r_blocks_count; // Reserved blocks count
+ uint32_t free_blocks_count; // Free blocks count
+ uint32_t free_inodes_count; // Free inodes count
+ uint32_t first_data_block; // First Data Block
+ uint32_t log_block_size; // Block size
+ uint32_t log_frag_size; // Fragment size
+ uint32_t blocks_per_group; // # Blocks per group
+ uint32_t frags_per_group; // # Fragments per group
+ uint32_t inodes_per_group; // # Inodes per group
+ uint32_t mtime; // Mount time
+ uint32_t wtime; // Write time
+ uint16_t mnt_count; // Mount count
+ uint16_t max_mnt_count; // Maximal mount count
+ uint16_t magic; // Magic signature
+ uint16_t state; // File system state
+ uint16_t errors; // Behaviour when detecting errors
+ uint16_t minor_rev_level; // minor revision level
+ uint32_t lastcheck; // time of last check
+ uint32_t checkinterval; // max. time between checks
+ uint32_t creator_os; // OS
+ uint32_t rev_level; // Revision level
+ uint16_t def_resuid; // Default uid for reserved blocks
+ uint16_t def_resgid; // Default gid for reserved blocks
+ uint32_t first_ino; // First non-reserved inode
+ uint16_t inode_size; // size of inode structure
+ uint16_t block_group_nr; // block group # of this superblock
+ uint32_t feature_compat; // compatible feature set
+ uint32_t feature_incompat; // incompatible feature set
+ uint32_t feature_ro_compat; // readonly-compatible feature set
+ char uuid[16]; // 128-bit uuid for volume
+ char volume_name[16]; // volume name
+ char last_mounted[64]; // directory where last mounted
+ uint32_t alg_usage_bitmap; // For compression
+ // For EXT2_COMPAT_PREALLOC
+ uint8_t prealloc_blocks; // Nr of blocks to try to preallocate
+ uint8_t prealloc_dir_blocks; //Nr to preallocate for dirs
+ uint16_t padding1;
+ // For EXT3_FEATURE_COMPAT_HAS_JOURNAL
+ uint8_t journal_uuid[16]; // uuid of journal superblock
+ uint32_t journal_inum; // inode number of journal file
+ uint32_t journal_dev; // device number of journal file
+ uint32_t last_orphan; // start of list of inodes to delete
+ uint32_t hash_seed[4]; // HTREE hash seed
+ uint8_t def_hash_version; // Default hash version to use
+ uint8_t padding2[3];
+ uint32_t default_mount_opts;
+ uint32_t first_meta_bg; // First metablock block group
+ uint32_t reserved[190]; // Padding to the end of the block
+};
+
+#define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001
+#define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
+#define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008
+#define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010
+#define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020
+
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
+
+#define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001
+#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
+
+#define EXT2_NAME_LEN 255
+
+struct ext2_dir_entry_2 {
+ uint32_t inode; // Inode number
+ uint16_t rec_len; // Directory entry length
+ uint8_t name_len; // Name length
+ uint8_t file_type;
+ char name[255]; // File name
+};
+
+// Ext2 directory file types. Only the low 3 bits are used. The
+// other bits are reserved for now.
+
+enum {
+ EXT2_FT_UNKNOWN,
+ EXT2_FT_REG_FILE,
+ EXT2_FT_DIR,
+ EXT2_FT_CHRDEV,
+ EXT2_FT_BLKDEV,
+ EXT2_FT_FIFO,
+ EXT2_FT_SOCK,
+ EXT2_FT_SYMLINK,
+ EXT2_FT_MAX
+};
+
+
+ // b - block size (1024, 2048, 4096)
+ // F - force (run on mounted device or non-block device)
+ // i - bytes per inode
+ // N - number of inodes
+ // m - reserved blocks percentage
+ // n - Don't write
+ // q - quiet
+
+ // L - volume label
+ // M - last mounted path
+ // o - creator os
+
+ // j - create journal
+ // J - journal options (size=1024-102400 blocks,device=)
+ // device=/dev/blah or LABEL=label UUID=uuid
+
+ // E - extended options (stride=stripe-size blocks)
+ // O - none,dir_index,filetype,has_journal,journal_dev,sparse_super
+
+
+// This is what's in a UUID according to the spec at
+// http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
+
+//struct uuid {
+// uint32_t time_low;
+// uint16_t time_mid;
+// uint16_t time_hi_and_version;
+// uint8_t clock_seq_hi_and_reserved;
+// uint8_t clock_seq_low;
+// uint8_t node[6];
+//};
+
+
+// According to http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
+// we should generate a uuid structure by reading a clock with 100 nanosecond
+// precision, normalizing it to the start of the gregorian calendar in 1582,
+// and looking up our eth0 mac address.
+//
+// On the other hand, we have 128 bits to come up with a unique identifier, of
+// which 6 have a defined value. /dev/urandom it is.
+
+void create_uuid(char *uuid)
+{
+ // Read 128 random bytes
+ int fd = xopen("/dev/urandom", O_RDONLY);
+ xreadall(fd, uuid, 16);
+ close(fd);
+
+ // Claim to be a DCE format UUID.
+ uuid[6] = (uuid[6] & 0x0F) | 0x40;
+ uuid[8] = (uuid[8] & 0x3F) | 0x80;
+
+ // rfc2518 section 6.4.1 suggests if we're not using a macaddr, we should
+ // set bit 1 of the node ID, which is the mac multicast bit. This means we
+ // should never collide with anybody actually using a macaddr.
+ uuid[11] = uuid[11] | 128;
+}
+
+int mke2fs_main(void)
+{
+ struct ext2_super_block *sb = xzalloc(sizeof(struct ext2_super_block));
+ int temp;
+
+ // Handle command line arguments.
+
+ if (!*toys.optargs || (!CFG_MKE2FS_GEN && toys.optargs[1])) usage_exit();
+ if (CFG_MKE2FS_GEN && toys.optargs[1]) {
+ temp = O_RDWR|O_CREAT;
+ xaccess(toys.optargs[1], R_OK);
+ } else temp = O_RDWR;
+ if (toy.mke2fs.blocksize!=1024 && toy.mke2fs.blocksize!=2048
+ && toy.mke2fs.blocksize!=4096) error_exit("bad blocksize");
+
+ // For mke?fs, open file. For gene?fs, create file.
+ toy.mke2fs.fsfd = xcreate(*toys.optargs, temp, 0777);
+
+ // We don't autodetect block size from external journaling devices, instead
+ // we write our block size to that journaling device. (If they want a
+ // specific block size, they have the -b option.)
+
+// What's the deal with fs_type?
+// line 1059
+
+ // We skip the first 1k (to avoid the boot sector, if any). Use this to
+ // figure out if this file is seekable.
+ if(-1 == lseek(toy.mke2fs.fsfd, 1024, SEEK_SET)) {
+ toy.mke2fs.noseek=1;
+ xwrite(toy.mke2fs.fsfd, sb, 1024);
+ }
+
+ // Fill out superblock structure
+
+ sb->rev_level = SWAP_LE32(1);
+ sb->feature_incompat = SWAP_LE32(EXT2_FEATURE_INCOMPAT_FILETYPE);
+ sb->feature_ro_compat = SWAP_LE32(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
+
+ // If we're called as mke3fs or mkfs.ext3, do a journal.
+
+ if (strchr(toys.which->name,'3'))
+ sb->feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
+
+ // Write superblock to disk.
+ xwrite(toy.mke2fs.fsfd, sb, 3072); // 4096-1024
+
+ return 0;
+}