.TH ARCHIVE_ENTRY_ACL 3 "February 15, 2017" ""
.SH NAME
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\fB\%archive_entry_acl_add_entry\fP,
\fB\%archive_entry_acl_add_entry_w\fP,
\fB\%archive_entry_acl_clear\fP,
\fB\%archive_entry_acl_count\fP,
\fB\%archive_entry_acl_from_text\fP,
\fB\%archive_entry_acl_from_text_w\fP,
\fB\%archive_entry_acl_next\fP,
\fB\%archive_entry_acl_next_w\fP,
\fB\%archive_entry_acl_reset\fP,
\fB\%archive_entry_acl_to_text\fP,
\fB\%archive_entry_acl_to_text_w\fP,
\fB\%archive_entry_acl_types\fP
\- functions for manipulating Access Control Lists in archive entry descriptions
.SH LIBRARY
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Streaming Archive Library (libarchive, -larchive)
.SH SYNOPSIS
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\fB#include <archive_entry.h>\fP
.br
\fIvoid\fP
.br
\fB\%archive_entry_acl_add_entry\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP, \fI\%int\ permset\fP, \fI\%int\ tag\fP, \fI\%int\ qualifier\fP, \fI\%const\ char\ *name\fP);
.br
\fIvoid\fP
.br
\fB\%archive_entry_acl_add_entry_w\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP, \fI\%int\ permset\fP, \fI\%int\ tag\fP, \fI\%int\ qualifier\fP, \fI\%const\ wchar_t\ *name\fP);
.br
\fIvoid\fP
.br
\fB\%archive_entry_acl_clear\fP(\fI\%struct\ archive_entry\ *a\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_count\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_from_text\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%const\ char\ *text\fP, \fI\%int\ type\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_from_text_w\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%const\ wchar_t\ *text\fP, \fI\%int\ type\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_next\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP, \fI\%int\ *ret_type\fP, \fI\%int\ *ret_permset\fP, \fI\%int\ *ret_tag\fP, \fI\%int\ *ret_qual\fP, \fI\%const\ char\ **ret_name\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_next_w\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP, \fI\%int\ *ret_type\fP, \fI\%int\ *ret_permset\fP, \fI\%int\ *ret_tag\fP, \fI\%int\ *ret_qual\fP, \fI\%const\ wchar_t\ **ret_name\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_reset\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%int\ type\fP);
.br
\fIchar *\fP
.br
\fB\%archive_entry_acl_to_text\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%ssize_t\ *len_p\fP, \fI\%int\ flags\fP);
.br
\fIwchar_t *\fP
.br
\fB\%archive_entry_acl_to_text_w\fP(\fI\%struct\ archive_entry\ *a\fP, \fI\%ssize_t\ *len_p\fP, \fI\%int\ flags\fP);
.br
\fIint\fP
.br
\fB\%archive_entry_acl_types\fP(\fI\%struct\ archive_entry\ *a\fP);
.SH DESCRIPTION
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The
``Access Control Lists (ACLs)''
extend the standard Unix perssion model.
The ACL interface of
\fB\%libarchive\fP
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.
.SS POSIX.1e Access Control Lists
A POSIX.1e ACL consists of a number of independent entries.
Each entry specifies the permission set as bitmask of basic permissions.
Valid permissions in the
are:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_READ (.B r )
.TP
.BR ARCHIVE_ENTRY_ACL_WRITE (.B w )
.TP
.BR ARCHIVE_ENTRY_ACL_EXECUTE (.B x )
.RE
The permissions correspond to the normal Unix permissions.
.PP
The
specifies the principal to which the permission applies.
Valid values are:
.RS 5
It .BR ARCHIVE_ENTRY_ACL_USER
The user specified by the name field.
It .BR ARCHIVE_ENTRY_ACL_USER_OBJ
The owner of the file.
It .BR ARCHIVE_ENTRY_ACL_GROUP
The group specied by the name field.
It .BR ARCHIVE_ENTRY_ACL_GROUP_OBJ
The group who owns the file.
It .BR ARCHIVE_ENTRY_ACL_MASK
The maximum permissions to be obtained via group permissions.
It .BR ARCHIVE_ENTRY_ACL_OTHER
Any principal who is not file owner or a member of the owning group.
.RE
.PP
The principals
.BR ARCHIVE_ENTRY_ACL_USER_OBJ,
.BR ARCHIVE_ENTRY_ACL_GROUP_OBJ
and
.BR ARCHIVE_ENTRY_ACL_OTHER
are equivalent to user, group and other in the classic Unix permission
model and specify non-extended ACL entries.
.PP
All files with have an access ACL
(.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS.)
This specifies the permissions required for access to the file itself.
Directories have an additional ACL
(.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT,)
which controls the initial access ACL for newly created directory entries.
.SS NFSv4 Access Control Lists
A NFSv4 ACL consists of multiple individual entries called Access Control
Entries (ACEs).
.PP
There are four possible types of a NFSv4 ACE:
.RS 5
It .BR ARCHIVE_ENTRY_ACL_TYPE_ALLOW
Allow principal to perform actions requiring given permissions.
It .BR ARCHIVE_ENTRY_ACL_TYPE_DENY
Prevent principal from performing actions requiring given permissions.
It .BR ARCHIVE_ENTRY_ACL_TYPE_AUDIT
Log access attempts by principal which require given permissions.
It .BR ARCHIVE_ENTRY_ACL_TYPE_ALARM
Trigger a system alarm on access attempts by principal which require given
permissions.
.RE
.PP
The
specifies the principal to which the permission applies.
Valid values are:
.RS 5
It .BR ARCHIVE_ENTRY_ACL_USER
The user specified by the name field.
It .BR ARCHIVE_ENTRY_ACL_USER_OBJ
The owner of the file.
It .BR ARCHIVE_ENTRY_ACL_GROUP
The group specied by the name field.
It .BR ARCHIVE_ENTRY_ACL_GROUP_OBJ
The group who owns the file.
It .BR ARCHIVE_ENTRY_ACL_EVERYONE
Any principal who is not file owner or a member of the owning group.
.RE
.PP
Entries with the
.BR ARCHIVE_ENTRY_ACL_USER
or
.BR ARCHIVE_ENTRY_ACL_GROUP
tag store the user and group name in the
string and optionally the user or group ID in the
integer.
.PP
NFSv4 ACE permissions and flags are stored in the same
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:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_READ_DATA (.B r )
Read data (file).
.TP
.BR ARCHIVE_ENTRY_ACL_LIST_DIRECTORY (.B r )
List entries (directory).
.TP
ARCHIVE_ENTRY_ACL_WRITE_DATA (.B w )
Write data (file).
.TP
ARCHIVE_ENTRY_ACL_ADD_FILE (.B w )
Create files (directory).
.TP
.BR ARCHIVE_ENTRY_ACL_EXECUTE (.B x )
Execute file or change into a directory.
.TP
.BR ARCHIVE_ENTRY_ACL_APPEND_DATA (.B p )
Append data (file).
.TP
.BR ARCHIVE_ENTRY_ACL_ADD_SUBDIRECTORY (.B p )
Create subdirectories (directory).
.TP
.BR ARCHIVE_ENTRY_ACL_DELETE_CHILD (.B D )
Remove files and subdirectories inside a directory.
.TP
.BR ARCHIVE_ENTRY_ACL_DELETE (.B d )
Remove file or directory.
.TP
.BR ARCHIVE_ENTRY_ACL_READ_ATTRIBUTES (.B a )
Read file or directory attributes.
.TP
.BR ARCHIVE_ENTRY_ACL_WRITE_ATTRIBUTES (.B A )
Write file or directory attributes.
.TP
.BR ARCHIVE_ENTRY_ACL_READ_NAMED_ATTRS (.B R )
Read named file or directory attributes.
.TP
.BR ARCHIVE_ENTRY_ACL_WRITE_NAMED_ATTRS (.B W )
Write named file or directory attributes.
.TP
.BR ARCHIVE_ENTRY_ACL_READ_ACL (.B c )
Read file or directory ACL.
.TP
.BR ARCHIVE_ENTRY_ACL_WRITE_ACL (.B C )
Write file or directory ACL.
.TP
.BR ARCHIVE_ENTRY_ACL_WRITE_OWNER (.B o )
Change owner of a file or directory.
.TP
.BR ARCHIVE_ENTRY_ACL_SYNCHRONIZE (.B s )
Use synchronous I/O.
.RE
.PP
The following NFSv4 ACL inheritance flags are supported:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_FILE_INHERIT (.B f )
Inherit parent directory ACE to files.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_DIRECTORY_INHERIT (.B d )
Inherit parent directory ACE to subdirectories.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_INHERIT_ONLY (.B i )
Only inherit, do not apply the permission on the directory itself.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_NO_PROPAGATE_INHERIT (.B n )
Do not propagate inherit flags. Only first-level entries inherit ACLs.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_SUCCESSFUL_ACCESS (.B S )
Trigger alarm or audit on successful access.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_FAILED_ACCESS (.B F )
Trigger alarm or audit on failed access.
.TP
.BR ARCHIVE_ENTRY_ACL_ENTRY_INHERITED (.B I )
Mark that ACE was inherited.
.RE
.SS Functions
\fB\%archive_entry_acl_add_entry\fP()
and
\fB\%archive_entry_acl_add_entry_w\fP()
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.
.PP
\fB\%archive_entry_acl_clear\fP()
removes all ACL entries and resets the enumeration pointer.
.PP
\fB\%archive_entry_acl_count\fP()
counts the ACL entries that have the given type mask.
can be the bitwise-or of
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
.RE
for POSIX.1e ACLs and
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_ALLOW
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_DENY
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_AUDIT
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_ALARM
.RE
for NFSv4 ACLs. For POSIX.1e ACLs if
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
is included and at least one extended ACL entry is found,
the three non-extended ACLs are added.
.PP
\fB\%archive_entry_acl_from_text\fP()
and
\fB\%archive_entry_acl_from_text_w\fP()
add new
(or merge with existing)
ACL entries from
(wide)
text. The argument
may take one of the following values:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_NFS4
.RE
Supports all formats that can be created with
\fB\%archive_entry_acl_to_text\fP()
or respective
\fB\%archive_entry_acl_to_text_w\fP().
Existing ACL entries are preserved. To get a clean new ACL from text
\fB\%archive_entry_acl_clear\fP()
must be called first. Entries prefixed with
``default:''
are treated as
.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
unless
is
.BR ARCHIVE_ENTRY_ACL_TYPE_NFS4.
Invalid entries, non-parseable ACL entries and entries beginning with
the
Sq #
character
(comments)
are skipped.
.PP
\fB\%archive_entry_acl_next\fP()
and
\fB\%archive_entry_acl_next_w\fP()
return the next entry of the ACL list.
This functions may only be called after
\fB\%archive_entry_acl_reset\fP()
has indicated the presence of extended ACL entries.
.PP
\fB\%archive_entry_acl_reset\fP()
prepare reading the list of ACL entries with
\fB\%archive_entry_acl_next\fP()
or
\fB\%archive_entry_acl_next_w\fP().
The function returns either 0, if no non-extended ACLs are found.
In this case, the access permissions should be obtained by
\fBarchive_entry_mode\fP(3)
or set using
\fBchmod\fP(2).
Otherwise, the function returns the same value as
\fB\%archive_entry_acl_count\fP().
.PP
\fB\%archive_entry_acl_to_text\fP()
and
\fB\%archive_entry_acl_to_text_w\fP()
convert the ACL entries for the given type into a
(wide)
string of ACL entries separated by newline. If the pointer
is not NULL, then the function shall return the length of the string
(not including the NULL terminator)
in the location pointed to by
.
The
argument is a bitwise-or.
.PP
The following flags are effective only on POSIX.1e ACL:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
Output access ACLs.
.TP
.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
Output POSIX.1e default ACLs.
.TP
.BR ARCHIVE_ENTRY_ACL_STYLE_MARK_DEFAULT
Prefix each default ACL entry with the word
``default:''.
.TP
.BR ARCHIVE_ENTRY_ACL_STYLE_SOLARIS
The mask and other ACLs don not contain a double colon.
.RE
.PP
The following flags are effecive only on NFSv4 ACL:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_STYLE_COMPACT
Do not output minus characters for unset permissions and flags in NFSv4 ACL
permission and flag fields.
.RE
.PP
The following flags are effective on both POSIX.1e and NFSv4 ACL:
.RS 5
.TP
.BR ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID
Add an additional colon-separated field containing the user or group id.
.TP
.BR ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA
Separate ACL entries with comma instead of newline.
.RE
.PP
If the archive entry contains NFSv4 ACLs, all types of NFSv4 ACLs are returned.
It the entry contains POSIX.1e ACLs and none of the flags
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
or
.BR ARCHIVE_ENTRY_ACL_TYPE_DEFAULT
are specified, both access and default entries are returned and default entries
are prefixed with
``default:''.
.PP
\fB\%archive_entry_acl_types\fP()
get ACL entry types contained in an archive entry's ACL. As POSIX.1e and NFSv4
ACL entries cannot be mixed, this function is a very efficient way to detect if
an ACL already contains POSIX.1e or NFSv4 ACL entries.
.SH RETURN VALUES
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\fB\%archive_entry_acl_count\fP()
and
\fB\%archive_entry_acl_reset\fP()
returns the number of ACL entries that match the given type mask.
For POSIX.1e ACLS if the type mask includes
.BR ARCHIVE_ENTRY_ACL_TYPE_ACCESS
and at least one extended ACL entry exists, the three classic Unix
permissions are counted.
.PP
\fB\%archive_entry_acl_from_text\fP()
and
\fB\%archive_entry_acl_from_text_w\fP()
return
.BR ARCHIVE_OK
if all entries were successfully parsed and
.BR ARCHIVE_WARN
if one or more entries were invalid or non-parseable.
.PP
\fB\%archive_entry_acl_next\fP()
and
\fB\%archive_entry_acl_next_w\fP()
return
.BR ARCHIVE_OK
on success,
.BR ARCHIVE_EOF
if no more ACL entries exist
and
.BR ARCHIVE_WARN
if
\fB\%archive_entry_acl_reset\fP()
has not been called first.
.PP
\fB\%archive_entry_acl_to_text\fP()
returns a string representing the ACL entries matching the given type and
flags on success or NULL on error.
.PP
\fB\%archive_entry_acl_to_text_w\fP()
returns a wide string representing the ACL entries matching the given type
and flags on success or NULL on error.
.PP
\fB\%archive_entry_acl_types\fP()
returns a bitmask of ACL entry types or 0 if archive entry has no ACL entries.
.SH SEE ALSO
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\fBarchive_entry\fP(3),
\fBlibarchive\fP(3)