ext2.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef EXT2_H
#define EXT2_H
 
#include "pedigree/kernel/processor/types.h"
 
#define EXT2_UNKNOWN 0x0
#define EXT2_FILE 0x1
#define EXT2_DIRECTORY 0x2
#define EXT2_CHAR_DEV 0x3
#define EXT2_BLOCK_DEV 0x4
#define EXT2_FIFO 0x5
#define EXT2_SOCKET 0x6
#define EXT2_SYMLINK 0x7
#define EXT2_MAX 0x8
 
#define EXT2_STATE_CLEAN 1
#define EXT2_STATE_UNCLEAN 2
 
#define EXT2_S_IFSOCK 0xC000
#define EXT2_S_IFLNK 0xA000
#define EXT2_S_IFREG 0x8000
#define EXT2_S_IFBLK 0x6000
#define EXT2_S_IFDIR 0x4000
#define EXT2_S_IFCHR 0x2000
#define EXT2_S_IFIFO 0x1000
 
#define EXT2_S_IRUSR 0x0100
#define EXT2_S_IWUSR 0x0080
#define EXT2_S_IXUSR 0x0040
#define EXT2_S_IRGRP 0x0020
#define EXT2_S_IWGRP 0x0010
#define EXT2_S_IXGRP 0x0008
#define EXT2_S_IROTH 0x0004
#define EXT2_S_IWOTH 0x0002
#define EXT2_S_IXOTH 0x0001
 
#define EXT2_BAD_INO 0x01          // Bad blocks inode
#define EXT2_ROOT_INO 0x02         // root directory inode
#define EXT2_ACL_IDX_INO 0x03      // ACL index inode (deprecated?)
#define EXT2_ACL_DATA_INO 0x04     // ACL data inode (deprecated?)
#define EXT2_BOOT_LOADER_INO 0x05  // boot loader inode
#define EXT2_UNDEL_DIR_INO 0x06
 
#define EXT2_LZV1_ALG 0x01
#define EXT2_LZRW3A_ALG 0x02
#define EXT2_GZIP_ALG 0x04
#define EXT2_BZIP2_ALG 0x08
#define EXT2_LZO_ALG 0x10
 
#define EXT2_SECRM_FL 0x00000001
#define EXT2_UNRM_FL 0x00000002
#define EXT2_COMPR_FL 0x00000004
#define EXT2_SYNC_FL 0x00000008
#define EXT2_IMMUTABLE_FL 0x00000010
#define EXT2_APPEND_FL 0x00000020
#define EXT2_NODUMP_FL 0x00000040
#define EXT2_NOATIME_FL 0x00000080
#define EXT2_DIRTY_FL 0x00000100
#define EXT2_COMPRBLK_FL 0x00000200
#define EXT2_NOCOMPR_FL 0x00000400
#define EXT2_ECOMPR_FL 0x00000800
#define EXT2_BTREE_FL 0x00001000
#define EXT2_INDEX_FL 0x00001000
#define EXT2_IMAGIC_FL 0x00002000
#define EXT3_JOURNAL_DATA_FL 0x00004000
#define EXT2_RESERVED_FL 0x80000000
 
struct Superblock {
  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;
  //   -- EXT2_DYNAMIC_REV Specific --
  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;
  char s_uuid[16];
 
  char s_volume_name[16];
  char s_last_mounted[64];
  uint32_t s_algo_bitmap;
  //   -- Performance Hints         --
  uint8_t s_prealloc_blocks;
  uint8_t s_prealloc_dir_blocks;
  uint16_t alignment;
  //   -- Journaling Support        --
  char s_journal_uuid[16];
  uint32_t s_journal_inum;
  uint32_t s_journal_dev;
  uint32_t s_last_orphan;
} __attribute__((packed));
 
struct GroupDesc {
  uint32_t bg_block_bitmap;
  uint32_t bg_inode_bitmap;
  uint32_t bg_inode_table;
  uint16_t bg_free_blocks_count;
  uint16_t bg_free_inodes_count;
  uint16_t bg_used_dirs_count;
  uint16_t bg_pad;
  uint8_t bg_reserved[12];
} __attribute__((packed));
 
constexpr uint32_t EXT2_FEATURE_COMPAT_EXT_ATTR = 0x8;
 
struct Inode {
  uint16_t i_mode;
  uint16_t i_uid;
  uint32_t i_size;
  uint32_t i_atime;
  uint32_t i_ctime;
  uint32_t i_mtime;
  uint32_t i_dtime;
  uint16_t i_gid;
  uint16_t i_links_count;
  uint32_t i_blocks;
  uint32_t i_flags;
  uint32_t i_osd1;
  uint32_t i_block[15];
  uint32_t i_generation;
  uint32_t i_file_acl;
  uint32_t i_dir_acl;  // Top 32-bits of file size.
  uint32_t i_faddr;
  uint8_t i_osd2[12];
} __attribute__((packed));
 
// Linux/Hurd encode the high owner halves in these two OS-dependent fields.
namespace Ext2Owner {
inline uint16_t read16(const void* field) {
  const auto* bytes = static_cast<const uint8_t*>(field);
  return static_cast<uint16_t>(bytes[0]) | (static_cast<uint16_t>(bytes[1]) << 8);
}
inline void write16(void* field, uint16_t value) {
  auto* bytes = static_cast<uint8_t*>(field);
  bytes[0] = value;
  bytes[1] = value >> 8;
}
inline uint32_t uid(const Inode& inode) {
  return read16(&inode.i_uid) | (static_cast<uint32_t>(read16(inode.i_osd2 + 4)) << 16);
}
inline uint32_t gid(const Inode& inode) {
  return read16(&inode.i_gid) | (static_cast<uint32_t>(read16(inode.i_osd2 + 6)) << 16);
}
inline void setUid(Inode& inode, uint32_t value) {
  write16(&inode.i_uid, value);
  write16(inode.i_osd2 + 4, value >> 16);
}
inline void setGid(Inode& inode, uint32_t value) {
  write16(&inode.i_gid, value);
  write16(inode.i_osd2 + 6, value >> 16);
}
}  // namespace Ext2Owner
 
struct Dir {
  uint32_t d_inode;
  uint16_t d_reclen;
  uint8_t d_namelen;
  uint8_t d_file_type;
  char d_name[256];
} __attribute__((packed));
 
#endif