Robert Watson a70f27470f Introduce support for POSIX.1e ACLs on UFS-based file systems. This ... implementation is still experimental, and while fairly broadly tested, is not yet intended for production use. Support for POSIX.1e ACLs on UFS will not be MFC'd to RELENG_4. This implementation works by providing implementations of VOP_[GS]ETACL() for FFS, as well as modifying the appropriate access control and file creation routines. In this implementation, ACLs are backed into extended attributes; the base ACL (owner, group, other) permissions remain in the inode for performance and compatibility reasons, so only the extended and default ACLs are placed in extended attributes. The logic for ACL evaluation is provided by the fs-independent kern/kern_acl.c. o Introduce UFS_ACL, a compile-time configuration option that enables support for ACLs on FFS (and potentially other UFS-based file systems). o Introduce ufs_getacl(), ufs_setacl(), ufs_aclcheck(), which respectively get, set, and check the ACLs on the passed vnode. o Introduce ufs_sync_acl_from_inode(), ufs_sync_inode_from_acl() to maintain access control information between inode permissions and extended attribute data. o Modify ufs_access() to load a file access ACL and invoke vaccess_acl_posix1e() if ACLs are available on the file system o Modify ufs_mkdir() and ufs_makeinode() to associate ACLs with newly created directories and files, inheriting from the parent directory's default ACL. o Enable these new vnode operations and conditionally compiled code paths if UFS_ACL is defined. A few notes: o This implementation is fairly widely tested, but still should be considered experimental. o Currently, ACLs are not exported via NFS, instead, the summarizing file mode/etc from the inode is. This results in conservative protection behavior, similar to the behavior of ACL-nonaware programs acting locally. o It is possible that underlying binary data formats associated with this implementation may change. Consumers of the implementation should expect to find their local configuration obsoleted in the next few months, resulting in possible loss of ACL data during an upgrade. o The extended attributes interface and implementation is still undergoing modification to address portable interface concerns, as well as performance. o Many applications do not yet correctly handle ACLs. In general, due to the POSIX.1e ACL model, behavior of ACL-unaware applications will be conservative with respects to file protection; some caution is recommended. o Instructions for configuring and maintaining ACLs on UFS will be committed in the near future; in the mean time it is possible to reference the README included in the last UFS ACL distribution placed in the TrustedBSD web site: http://www.TrustedBSD.org/downloads/ Substantial debugging, hardware, travel, or connectivity support for this project was provided by: BSDi, Safeport Network Services, and NAI Labs. Significant coding contributions were made by Chris Faulhaber. Additional support was provided by Brian Feldman, Thomas Moestl, and Ilmar Habibulin. Reviewed by: jedgar, keichii, mckusick, trustedbsd-discuss, freebsd-fs Obtained from: TrustedBSD Project		2001-03-26 17:53:19 +00:00
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ufs	Introduce support for POSIX.1e ACLs on UFS-based file systems. This	2001-03-26 17:53:19 +00:00