1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #ifndef __XFS_ATTR_H__ 7 #define __XFS_ATTR_H__ 8 9 struct xfs_inode; 10 struct xfs_da_args; 11 struct xfs_attr_list_context; 12 13 /* 14 * Large attribute lists are structured around Btrees where all the data 15 * elements are in the leaf nodes. Attribute names are hashed into an int, 16 * then that int is used as the index into the Btree. Since the hashval 17 * of an attribute name may not be unique, we may have duplicate keys. 18 * The internal links in the Btree are logical block offsets into the file. 19 * 20 * Small attribute lists use a different format and are packed as tightly 21 * as possible so as to fit into the literal area of the inode. 22 */ 23 24 /*======================================================================== 25 * External interfaces 26 *========================================================================*/ 27 28 29 #define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */ 30 #define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */ 31 #define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */ 32 #define ATTR_SECURE 0x0008 /* use attrs in security namespace */ 33 #define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */ 34 #define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */ 35 36 #define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */ 37 #define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */ 38 39 #define ATTR_INCOMPLETE 0x4000 /* [kernel] return INCOMPLETE attr keys */ 40 #define ATTR_ALLOC 0x8000 /* allocate xattr buffer on demand */ 41 42 #define XFS_ATTR_FLAGS \ 43 { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \ 44 { ATTR_ROOT, "ROOT" }, \ 45 { ATTR_TRUST, "TRUST" }, \ 46 { ATTR_SECURE, "SECURE" }, \ 47 { ATTR_CREATE, "CREATE" }, \ 48 { ATTR_REPLACE, "REPLACE" }, \ 49 { ATTR_KERNOTIME, "KERNOTIME" }, \ 50 { ATTR_KERNOVAL, "KERNOVAL" }, \ 51 { ATTR_INCOMPLETE, "INCOMPLETE" }, \ 52 { ATTR_ALLOC, "ALLOC" } 53 54 /* 55 * The maximum size (into the kernel or returned from the kernel) of an 56 * attribute value or the buffer used for an attr_list() call. Larger 57 * sizes will result in an ERANGE return code. 58 */ 59 #define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */ 60 61 /* 62 * Define how lists of attribute names are returned to the user from 63 * the attr_list() call. A large, 32bit aligned, buffer is passed in 64 * along with its size. We put an array of offsets at the top that each 65 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom. 66 */ 67 typedef struct attrlist { 68 __s32 al_count; /* number of entries in attrlist */ 69 __s32 al_more; /* T/F: more attrs (do call again) */ 70 __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */ 71 } attrlist_t; 72 73 /* 74 * Show the interesting info about one attribute. This is what the 75 * al_offset[i] entry points to. 76 */ 77 typedef struct attrlist_ent { /* data from attr_list() */ 78 __u32 a_valuelen; /* number bytes in value of attr */ 79 char a_name[1]; /* attr name (NULL terminated) */ 80 } attrlist_ent_t; 81 82 /* 83 * Given a pointer to the (char*) buffer containing the attr_list() result, 84 * and an index, return a pointer to the indicated attribute in the buffer. 85 */ 86 #define ATTR_ENTRY(buffer, index) \ 87 ((attrlist_ent_t *) \ 88 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ]) 89 90 /* 91 * Kernel-internal version of the attrlist cursor. 92 */ 93 typedef struct attrlist_cursor_kern { 94 __u32 hashval; /* hash value of next entry to add */ 95 __u32 blkno; /* block containing entry (suggestion) */ 96 __u32 offset; /* offset in list of equal-hashvals */ 97 __u16 pad1; /* padding to match user-level */ 98 __u8 pad2; /* padding to match user-level */ 99 __u8 initted; /* T/F: cursor has been initialized */ 100 } attrlist_cursor_kern_t; 101 102 103 /*======================================================================== 104 * Structure used to pass context around among the routines. 105 *========================================================================*/ 106 107 108 /* void; state communicated via *context */ 109 typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int, 110 unsigned char *, int, int); 111 112 typedef struct xfs_attr_list_context { 113 struct xfs_trans *tp; 114 struct xfs_inode *dp; /* inode */ 115 struct attrlist_cursor_kern *cursor; /* position in list */ 116 char *alist; /* output buffer */ 117 118 /* 119 * Abort attribute list iteration if non-zero. Can be used to pass 120 * error values to the xfs_attr_list caller. 121 */ 122 int seen_enough; 123 124 ssize_t count; /* num used entries */ 125 int dupcnt; /* count dup hashvals seen */ 126 int bufsize; /* total buffer size */ 127 int firstu; /* first used byte in buffer */ 128 int flags; /* from VOP call */ 129 int resynch; /* T/F: resynch with cursor */ 130 put_listent_func_t put_listent; /* list output fmt function */ 131 int index; /* index into output buffer */ 132 } xfs_attr_list_context_t; 133 134 135 /*======================================================================== 136 * Function prototypes for the kernel. 137 *========================================================================*/ 138 139 /* 140 * Overall external interface routines. 141 */ 142 int xfs_attr_inactive(struct xfs_inode *dp); 143 int xfs_attr_list_int_ilocked(struct xfs_attr_list_context *); 144 int xfs_attr_list_int(struct xfs_attr_list_context *); 145 int xfs_inode_hasattr(struct xfs_inode *ip); 146 int xfs_attr_get_ilocked(struct xfs_inode *ip, struct xfs_da_args *args); 147 int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name, 148 unsigned char **value, int *valuelenp, int flags); 149 int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name, 150 unsigned char *value, int valuelen, int flags); 151 int xfs_attr_set_args(struct xfs_da_args *args); 152 int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags); 153 int xfs_attr_remove_args(struct xfs_da_args *args); 154 int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize, 155 int flags, struct attrlist_cursor_kern *cursor); 156 bool xfs_attr_namecheck(const void *name, size_t length); 157 158 #endif /* __XFS_ATTR_H__ */ 159