Copyright (c) 1999-2001 Robert N. M. Watson
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$FreeBSD: head/share/man/man9/acl.9 88398 2001-12-22 03:46:33Z chris $
.Dd December 23, 1999 .Os .Dt ACL 9 .Sh NAME .Nm acl .Nd virtual file system access control lists .Sh SYNOPSIS n sys/param.h n sys/vnode.h n sys/acl.h
p d -literal typedef int acl_type_t; typedef int acl_tag_t; typedef mode_t acl_perm_t; typedef mode_t *acl_permset_t; struct acl_entry { acl_tag_t ae_tag; uid_t ae_id; acl_perm_t ae_perm; }; typedef struct acl_entry *acl_entry_t; /* internal ACL structure */ struct acl { int acl_cnt; struct acl_entry acl_entry[ACL_MAX_ENTRIES]; }; /* external ACL structure */ struct acl_t_struct { struct acl ats_acl; int ats_cur_entry; }; typedef struct acl_t_struct *acl_t; /* * Possible valid values for ae_tag field. */ #define ACL_UNDEFINED_TAG 0x00000000 #define ACL_USER_OBJ 0x00000001 #define ACL_USER 0x00000002 #define ACL_GROUP_OBJ 0x00000004 #define ACL_GROUP 0x00000008 #define ACL_MASK 0x00000010 #define ACL_OTHER 0x00000020 #define ACL_OTHER_OBJ ACL_OTHER /* * Possible valid values for acl_type_t arguments. */ #define ACL_TYPE_ACCESS 0x00000000 #define ACL_TYPE_DEFAULT 0x00000001 #define ACL_TYPE_AFS 0x00000002 #define ACL_TYPE_CODA 0x00000003 #define ACL_TYPE_NTFS 0x00000004 #define ACL_TYPE_NWFS 0x00000005 /* * Possible flags in ae_perm field. */ #define ACL_EXECUTE 0x0001 #define ACL_WRITE 0x0002 #define ACL_READ 0x0004 #define ACL_PERM_NONE 0x0000 #define ACL_PERM_BITS (ACL_EXECUTE | ACL_WRITE | ACL_READ) #define ACL_POSIX1E_BITS (ACL_EXECUTE | ACL_WRITE | ACL_READ) /* * Possible entry_id values for acl_get_entry() */ #define ACL_FIRST_ENTRY 0 #define ACL_NEXT_ENTRY 1 /* * Undefined value in ae_id field */ #define ACL_UNDEFINED_ID ((uid_t)-1) .Ed .Sh DESCRIPTION Access control lists, or ACLs, allow fine-grained specification of rights for vnodes representing files and directories. However, as there are a plethora of file systems with differing ACL semantics, the vnode interface is aware only of the syntax of ACLs, relying on the underlying file system to implement the details. Depending on the underlying file system, each file or directory may have zero or more ACLs associated with it, named using the .Fa type field of the appropriate vnode ACL calls, .Xr VOP_ACLCHECK 9 , .Xr VOP_GETACL 9 , and .Xr VOP_SETACL 9 .
p Currently, each ACL is represented in-kernel by a fixed-size acl structure. An ACL is constructed from a fixed size array of ACL entries, each of which consists of a set of permissions, principal namespace, and principal identifier. Zero or more of these entries may be "defined", depending on the value of the associated acl_cnt field. .Sh SEE ALSO .Xr acl 3 , .Xr vaccess 9 , .Xr vaccess_acl_posix1e 9 , .Xr VFS 9 , .Xr VOP_ACLCHECK 9 , .Xr VOP_GETACL 9 , .Xr VOP_SETACL 9 .Sh AUTHORS This man page was written by .An Robert Watson .