1 /* 2 * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com) 3 * Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com) 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * - Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * - The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /** @addtogroup lwext4 30 * @{ 31 */ 32 /** 33 * @file ext4_xattr.h 34 * @brief Extended Attribute manipulation. 35 */ 36 37 #ifndef EXT4_XATTR_H_ 38 #define EXT4_XATTR_H_ 39 40 #include <ext2fs.h> 41 #include <linux/rbtree.h> 42 43 /* Extended Attribute(EA) */ 44 45 /* Magic value in attribute blocks */ 46 #define EXT4_XATTR_MAGIC 0xEA020000 47 48 /* Maximum number of references to one attribute block */ 49 #define EXT4_XATTR_REFCOUNT_MAX 1024 50 51 /* Name indexes */ 52 #define EXT4_XATTR_INDEX_USER 1 53 #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2 54 #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3 55 #define EXT4_XATTR_INDEX_TRUSTED 4 56 #define EXT4_XATTR_INDEX_LUSTRE 5 57 #define EXT4_XATTR_INDEX_SECURITY 6 58 #define EXT4_XATTR_INDEX_SYSTEM 7 59 #define EXT4_XATTR_INDEX_RICHACL 8 60 #define EXT4_XATTR_INDEX_ENCRYPTION 9 61 62 #pragma pack(push, 1) 63 64 struct ext4_xattr_header { 65 __le32 h_magic; /* magic number for identification */ 66 __le32 h_refcount; /* reference count */ 67 __le32 h_blocks; /* number of disk blocks used */ 68 __le32 h_hash; /* hash value of all attributes */ 69 __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ 70 /* id = inum if refcount=1, blknum otherwise */ 71 __le32 h_reserved[3]; /* zero right now */ 72 }; 73 74 struct ext4_xattr_ibody_header { 75 __le32 h_magic; /* magic number for identification */ 76 }; 77 78 struct ext4_xattr_entry { 79 __u8 e_name_len; /* length of name */ 80 __u8 e_name_index; /* attribute name index */ 81 __le16 e_value_offs; /* offset in disk block of value */ 82 __le32 e_value_block; /* disk block attribute is stored on (n/i) */ 83 __le32 e_value_size; /* size of attribute value */ 84 __le32 e_hash; /* hash value of name and value */ 85 }; 86 87 #pragma pack(pop) 88 89 #define EXT4_GOOD_OLD_INODE_SIZE EXT2_GOOD_OLD_INODE_SIZE 90 91 #define EXT4_XATTR_PAD_BITS 2 92 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS) 93 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1) 94 #define EXT4_XATTR_LEN(name_len) \ 95 (((name_len) + EXT4_XATTR_ROUND + \ 96 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND) 97 #define EXT4_XATTR_NEXT(entry) \ 98 ((struct ext4_xattr_entry *)( \ 99 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) 100 #define EXT4_XATTR_SIZE(size) \ 101 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) 102 #define EXT4_XATTR_NAME(entry) \ 103 ((char *)((entry) + 1)) 104 105 #define EXT4_XATTR_IHDR(raw_inode) \ 106 ((struct ext4_xattr_ibody_header *) \ 107 ((char *)raw_inode + \ 108 EXT4_GOOD_OLD_INODE_SIZE + \ 109 (raw_inode)->i_extra_isize)) 110 #define EXT4_XATTR_IFIRST(hdr) \ 111 ((struct ext4_xattr_entry *)((hdr)+1)) 112 113 #define EXT4_XATTR_BHDR(block) \ 114 ((struct ext4_xattr_header *)((block)->b_data)) 115 #define EXT4_XATTR_ENTRY(ptr) \ 116 ((struct ext4_xattr_entry *)(ptr)) 117 #define EXT4_XATTR_BFIRST(block) \ 118 EXT4_XATTR_ENTRY(EXT4_XATTR_BHDR(block)+1) 119 #define EXT4_XATTR_IS_LAST_ENTRY(entry) \ 120 (*(__le32 *)(entry) == 0) 121 122 #define EXT4_ZERO_XATTR_VALUE ((void *)-1) 123 124 125 struct ext4_xattr_item { 126 /* This attribute should be stored in inode body */ 127 BOOL in_inode; 128 BOOL is_data; 129 130 __u8 name_index; 131 char *name; 132 size_t name_len; 133 void *data; 134 size_t data_size; 135 136 struct rb_node node; 137 struct list_head list_node; 138 }; 139 140 struct ext4_xattr_ref { 141 PEXT2_IRP_CONTEXT IrpContext; 142 BOOL block_loaded; 143 struct buffer_head *block_bh; 144 PEXT2_MCB inode_ref; 145 146 PEXT2_INODE OnDiskInode; 147 BOOL IsOnDiskInodeDirty; 148 149 BOOL dirty; 150 size_t ea_size; 151 size_t inode_size_rem; 152 size_t block_size_rem; 153 PEXT2_VCB fs; 154 155 void *iter_arg; 156 struct ext4_xattr_item *iter_from; 157 158 struct rb_root root; 159 struct list_head ordered_list; 160 }; 161 162 #define EXT4_XATTR_ITERATE_CONT 0 163 #define EXT4_XATTR_ITERATE_STOP 1 164 #define EXT4_XATTR_ITERATE_PAUSE 2 165 166 int ext4_fs_get_xattr_ref(PEXT2_IRP_CONTEXT IrpContext, PEXT2_VCB fs, PEXT2_MCB inode_ref, 167 struct ext4_xattr_ref *ref); 168 169 int ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref); 170 171 int ext4_fs_set_xattr(struct ext4_xattr_ref *ref, __u8 name_index, 172 const char *name, size_t name_len, const void *data, 173 size_t data_size, BOOL replace); 174 175 int ext4_fs_set_xattr_ordered(struct ext4_xattr_ref *ref, __u8 name_index, 176 const char *name, size_t name_len, const void *data, 177 size_t data_size); 178 179 int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref, __u8 name_index, 180 const char *name, size_t name_len); 181 182 int ext4_fs_get_xattr(struct ext4_xattr_ref *ref, __u8 name_index, 183 const char *name, size_t name_len, void *buf, 184 size_t buf_size, size_t *data_size); 185 186 void ext4_fs_xattr_iterate(struct ext4_xattr_ref *ref, 187 int(*iter)(struct ext4_xattr_ref *ref, 188 struct ext4_xattr_item *item, 189 BOOL is_last)); 190 191 void ext4_fs_xattr_iterate_reset(struct ext4_xattr_ref *ref); 192 193 const char *ext4_extract_xattr_name(const char *full_name, size_t full_name_len, 194 __u8 *name_index, size_t *name_len, 195 BOOL *found); 196 197 const char *ext4_get_xattr_name_prefix(__u8 name_index, 198 size_t *ret_prefix_len); 199 200 void ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref); 201 202 #endif 203 /** 204 * @} 205 */ 206