retro-imager/dependencies/libarchive-3.5.2/doc/text/archive_entry_acl.3.txt

ARCHIVE_ENTRY_ACL(3)	 BSD Library Functions Manual	  ARCHIVE_ENTRY_ACL(3)

NAME
     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
     Streaming Archive Library (libarchive, -larchive)

SYNOPSIS
     #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);

DESCRIPTION
     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.

   POSIX.1e Access Control Lists
     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 spec‐
     ifies the permissions required for access to the file itself.  Directo‐
     ries have an additional ACL (ARCHIVE_ENTRY_ACL_TYPE_DEFAULT), which con‐
     trols the initial access ACL for newly-created directory entries.

   NFSv4 Access Control Lists
     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 re‐
					quiring given permissions.
	   ARCHIVE_ENTRY_ACL_TYPE_DENY	Prevent principal from performing ac‐
					tions 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 at‐
					tempts 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.

   Functions
     archive_entry_acl_add_entry() and archive_entry_acl_add_entry_w() add a
     single ACL entry.	For the access ACL and non-extended principals, the
     classic Unix permissions are updated.  An archive entry cannot contain
     both POSIX.1e and NFSv4 ACL entries.

     archive_entry_acl_clear() removes all ACL entries and resets the enumera‐
     tion pointer.

     archive_entry_acl_count() counts the ACL entries that have the given type
     mask.  type can be the bitwise-or of
	   ARCHIVE_ENTRY_ACL_TYPE_ACCESS
	   ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
     for POSIX.1e ACLs and
	   ARCHIVE_ENTRY_ACL_TYPE_ALLOW
	   ARCHIVE_ENTRY_ACL_TYPE_DENY
	   ARCHIVE_ENTRY_ACL_TYPE_AUDIT
	   ARCHIVE_ENTRY_ACL_TYPE_ALARM
     for NFSv4 ACLs.  For POSIX.1e ACLs if ARCHIVE_ENTRY_ACL_TYPE_ACCESS is
     included and at least one extended ACL entry is found, the three non-ex‐
     tended ACLs are added.

     archive_entry_acl_from_text() and archive_entry_acl_from_text_w() add new
     (or merge with existing) ACL entries from (wide) text.  The argument type
     may take one of the following values:
	   ARCHIVE_ENTRY_ACL_TYPE_ACCESS
	   ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
	   ARCHIVE_ENTRY_ACL_TYPE_NFS4
     Supports all formats that can be created with archive_entry_acl_to_text()
     or respectively archive_entry_acl_to_text_w().  Existing ACL entries are
     preserved.  To get a clean new ACL from text archive_entry_acl_clear()
     must be called first.  Entries prefixed with “default:” are treated as
     ARCHIVE_ENTRY_ACL_TYPE_DEFAULT unless type is
     ARCHIVE_ENTRY_ACL_TYPE_NFS4.  Invalid entries, non-parseable ACL entries
     and entries beginning with the ‘#’ character (comments) are skipped.

     archive_entry_acl_next() return the next entry of the ACL list.  This
     functions may only be called after archive_entry_acl_reset() has indi‐
     cated the presence of extended ACL entries.

     archive_entry_acl_reset() prepare reading the list of ACL entries with
     archive_entry_acl_next().	The function returns 0 if no non-extended ACLs
     are found.  In this case, the access permissions should be obtained by
     archive_entry_mode(3) or set using chmod(2).  Otherwise, the function re‐
     turns the same value as archive_entry_acl_count().

     archive_entry_acl_to_text() and archive_entry_acl_to_text_w() convert the
     ACL entries for the given type into a (wide) string of ACL entries sepa‐
     rated by newline.	If the pointer len_p is not NULL, then the function
     shall return the length of the string (not including the NULL terminator)
     in the location pointed to by len_p.  The flag argument is a bitwise-or.

     The following flags are effective only on POSIX.1e ACL:
	   ARCHIVE_ENTRY_ACL_TYPE_ACCESS
		   Output access ACLs.
	   ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
		   Output POSIX.1e default ACLs.
	   ARCHIVE_ENTRY_ACL_STYLE_MARK_DEFAULT
		   Prefix each default ACL entry with the word “default:”.
	   ARCHIVE_ENTRY_ACL_STYLE_SOLARIS
		   The mask and other ACLs don not contain a double colon.

     The following flags are effecive only on NFSv4 ACL:
	   ARCHIVE_ENTRY_ACL_STYLE_COMPACT
		   Do not output minus characters for unset permissions and
		   flags in NFSv4 ACL permission and flag fields.

     The following flags are effective on both POSIX.1e and NFSv4 ACL:
	   ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID
		   Add an additional colon-separated field containing the user
		   or group id.
	   ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA
		   Separate ACL entries with comma instead of newline.

     If the archive entry contains NFSv4 ACLs, all types of NFSv4 ACLs are re‐
     turned.  It the entry contains POSIX.1e ACLs and none of the flags
     ARCHIVE_ENTRY_ACL_TYPE_ACCESS or ARCHIVE_ENTRY_ACL_TYPE_DEFAULT are spec‐
     ified, both access and default entries are returned and default entries
     are prefixed with “default:”.

     archive_entry_acl_types() get ACL entry types contained in an archive en‐
     try's ACL.  As POSIX.1e and NFSv4 ACL entries cannot be mixed, this func‐
     tion is a very efficient way to detect if an ACL already contains
     POSIX.1e or NFSv4 ACL entries.

RETURN VALUES
     archive_entry_acl_count() and archive_entry_acl_reset() returns the num‐
     ber 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 ex‐
     tended 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.

SEE ALSO
     archive_entry(3), libarchive(3)

BSD			       February 15, 2017			   BSD