Manual Pages  — ARCHIVE_ENTRY_ACL

archive_entry_acl_add_entry, archive_entry_acl_add_entry_w, archive_entry_acl_clear, archive_entry_acl_count, archive_entry_acl_from_text, archive_entry_acl_from_text_w, archive_entry_acl_next, archive_entry_acl_reset, archive_entry_acl_to_text, archive_entry_acl_to_text_w, archive_entry_acl_types – functions for manipulating Access Control Lists in archive entry descriptions

LIBRARY SYNOPSIS DESCRIPTION POSIX.1e Access Control Lists NFSv4 Access Control Lists Functions RETURN VALUES SEE ALSO

Streaming Archive Library (libarchive, -larchive)

#include <archive_entry.h>

void
archive_entry_acl_add_entry(struct archive_entry *a, int type, int permset, int tag, int qualifier, const char *name);

void
archive_entry_acl_add_entry_w(struct archive_entry *a, int type, int permset, int tag, int qualifier, const wchar_t *name);

void
archive_entry_acl_clear(struct archive_entry *a);

int
archive_entry_acl_count(struct archive_entry *a, int type);

int
archive_entry_acl_from_text(struct archive_entry *a, const char *text, int type);

int
archive_entry_acl_from_text_w(struct archive_entry *a, const wchar_t *text, int type);

int
archive_entry_acl_next(struct archive_entry *a, int type, int *ret_type, int *ret_permset, int *ret_tag, int *ret_qual, const char **ret_name);

int
archive_entry_acl_reset(struct archive_entry *a, int type);

char *
archive_entry_acl_to_text(struct archive_entry *a, ssize_t *len_p, int flags);

wchar_t *
archive_entry_acl_to_text_w(struct archive_entry *a, ssize_t *len_p, int flags);

int
archive_entry_acl_types(struct archive_entry *a);

The "Access Control Lists (ACLs)" extend the standard Unix permission model. The ACL interface of libarchive supports both POSIX.1e and NFSv4 style ACLs. Use of ACLs is restricted by various levels of ACL support in operating systems, file systems and archive formats.

A POSIX.1e ACL consists of a number of independent entries. Each entry specifies the permission set as a bitmask of basic permissions. Valid permissions in the permset are:

ARCHIVE_ENTRY_ACL_READ( r) ARCHIVE_ENTRY_ACL_WRITE( w) ARCHIVE_ENTRY_ACL_EXECUTE( x)

The permissions correspond to the normal Unix permissions.

The tag specifies the principal to which the permission applies. Valid values are:

ARCHIVE_ENTRY_ACL_USER	The user specified by the name field.
ARCHIVE_ENTRY_ACL_USER_OBJ	The owner of the file.
ARCHIVE_ENTRY_ACL_GROUP	The group specified by the name field.
ARCHIVE_ENTRY_ACL_GROUP_OBJ	The group which owns the file.
ARCHIVE_ENTRY_ACL_MASK	The maximum permissions to be obtained via group permissions.
ARCHIVE_ENTRY_ACL_OTHER	Any principal who is not the file owner or a member of the owning group.

The principals ARCHIVE_ENTRY_ACL_USER_OBJ, ARCHIVE_ENTRY_ACL_GROUP_OBJ and ARCHIVE_ENTRY_ACL_OTHER are equivalent to user, group and other in the classic Unix permission model and specify non-extended ACL entries.

All files have an access ACL ( ARCHIVE_ENTRY_ACL_TYPE_ACCESS). This specifies the permissions required for access to the file itself. Directories have an additional ACL ( ARCHIVE_ENTRY_ACL_TYPE_DEFAULT), which controls the initial access ACL for newly-created directory entries.

A NFSv4 ACL consists of multiple individual entries called Access Control Entries (ACEs).

There are four possible types of a NFSv4 ACE:

ARCHIVE_ENTRY_ACL_TYPE_ALLOW	Allow principal to perform actions requiring given permissions.
ARCHIVE_ENTRY_ACL_TYPE_DENY	Prevent principal from performing actions requiring given permissions.
ARCHIVE_ENTRY_ACL_TYPE_AUDIT	Log access attempts by principal which require given permissions.
ARCHIVE_ENTRY_ACL_TYPE_ALARM	Trigger a system alarm on access attempts by principal which require given permissions.

The tag specifies the principal to which the permission applies. Valid values are:

ARCHIVE_ENTRY_ACL_USER	The user specified by the name field.
ARCHIVE_ENTRY_ACL_USER_OBJ	The owner of the file.
ARCHIVE_ENTRY_ACL_GROUP	The group specified by the name field.
ARCHIVE_ENTRY_ACL_GROUP_OBJ	The group which owns the file.
ARCHIVE_ENTRY_ACL_EVERYONE	Any principal who is not the file owner or a member of the owning group.

Entries with the ARCHIVE_ENTRY_ACL_USER or ARCHIVE_ENTRY_ACL_GROUP tag store the user and group name in the name string and optionally the user or group ID in the qualifier integer.

NFSv4 ACE permissions and flags are stored in the same permset bitfield. Some permissions share the same constant and permission character but have different effect on directories than on files. The following ACE permissions are supported:

ARCHIVE_ENTRY_ACL_READ_DATA( r)	Read data (file).
ARCHIVE_ENTRY_ACL_LIST_DIRECTORY( r)	List entries (directory).
ARCHIVE_ENTRY_ACL_WRITE_DATA( w)	Write data (file).
ARCHIVE_ENTRY_ACL_ADD_FILE( w)	Create files (directory).
ARCHIVE_ENTRY_ACL_EXECUTE( x)	Execute file or change into a directory.
ARCHIVE_ENTRY_ACL_APPEND_DATA( p)	Append data (file).
ARCHIVE_ENTRY_ACL_ADD_SUBDIRECTORY( p)	Create subdirectories (directory).
ARCHIVE_ENTRY_ACL_DELETE_CHILD( D)	Remove files and subdirectories inside a directory.
ARCHIVE_ENTRY_ACL_DELETE( d)	Remove file or directory.
ARCHIVE_ENTRY_ACL_READ_ATTRIBUTES( a)	Read file or directory attributes.
ARCHIVE_ENTRY_ACL_WRITE_ATTRIBUTES( A)	Write file or directory attributes.
ARCHIVE_ENTRY_ACL_READ_NAMED_ATTRS( R)	Read named file or directory attributes.
ARCHIVE_ENTRY_ACL_WRITE_NAMED_ATTRS( W)	Write named file or directory attributes.
ARCHIVE_ENTRY_ACL_READ_ACL( c)	Read file or directory ACL.
ARCHIVE_ENTRY_ACL_WRITE_ACL( C)	Write file or directory ACL.
ARCHIVE_ENTRY_ACL_WRITE_OWNER( o)	Change owner of a file or directory.
ARCHIVE_ENTRY_ACL_SYNCHRONIZE( s)	Use synchronous I/O.

The following NFSv4 ACL inheritance flags are supported:

ARCHIVE_ENTRY_ACL_ENTRY_FILE_INHERIT( f)	Inherit parent directory ACE to files.
ARCHIVE_ENTRY_ACL_ENTRY_DIRECTORY_INHERIT( d)	Inherit parent directory ACE to subdirectories.
ARCHIVE_ENTRY_ACL_ENTRY_INHERIT_ONLY( i)	Only inherit, do not apply the permission on the directory itself.
ARCHIVE_ENTRY_ACL_ENTRY_NO_PROPAGATE_INHERIT( n)	Do not propagate inherit flags. Only first-level entries inherit ACLs.
ARCHIVE_ENTRY_ACL_ENTRY_SUCCESSFUL_ACCESS( S)	Trigger alarm or audit on successful access.
ARCHIVE_ENTRY_ACL_ENTRY_FAILED_ACCESS( F)	Trigger alarm or audit on failed access.
ARCHIVE_ENTRY_ACL_ENTRY_INHERITED( I)	Mark that ACE was inherited.

archive_entry_acl_count() and archive_entry_acl_reset() returns the number of ACL entries that match the given type mask. For POSIX.1e ACLS if the type mask includes ARCHIVE_ENTRY_ACL_TYPE_ACCESS and at least one extended ACL entry exists, the three classic Unix permissions are counted.

archive_entry_acl_from_text() and archive_entry_acl_from_text_w() return ARCHIVE_OK if all entries were successfully parsed and ARCHIVE_WARN if one or more entries were invalid or non-parseable.

archive_entry_acl_next() returns ARCHIVE_OK on success, ARCHIVE_EOF if no more ACL entries exist and ARCHIVE_WARN if archive_entry_acl_reset() has not been called first.

archive_entry_acl_to_text() returns a string representing the ACL entries matching the given type and flags on success or NULL on error.

archive_entry_acl_to_text_w() returns a wide string representing the ACL entries matching the given type and flags on success or NULL on error.

archive_entry_acl_types() returns a bitmask of ACL entry types or 0 if archive entry has no ACL entries.