.\" Copyright (c) 2010 Joerg Sonnenberger

.\" Copyright (c) 2016 Martin Matuska

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.Dd February 15, 2017

.Dt ARCHIVE_ENTRY_ACL 3

.Os

.Sh NAME

.Nm archive_entry_acl_add_entry ,

.Nm archive_entry_acl_add_entry_w ,

.Nm archive_entry_acl_clear ,

.Nm archive_entry_acl_count ,

.Nm archive_entry_acl_from_text ,

.Nm archive_entry_acl_from_text_w ,

.Nm archive_entry_acl_next ,

.Nm archive_entry_acl_next_w ,

.Nm archive_entry_acl_reset ,

.Nm archive_entry_acl_to_text ,

.Nm archive_entry_acl_to_text_w ,

.Nm archive_entry_acl_types

.Nd functions for manipulating Access Control Lists in archive entry descriptions

.Sh LIBRARY

Streaming Archive Library (libarchive, -larchive)

.Sh SYNOPSIS

.In archive_entry.h

.Ft void

.Fo archive_entry_acl_add_entry

.Fa "struct archive_entry *a"

.Fa "int type"

.Fa "int permset"

.Fa "int tag"

.Fa "int qualifier"

.Fa "const char *name"

.Fc

.Ft void

.Fo archive_entry_acl_add_entry_w

.Fa "struct archive_entry *a"

.Fa "int type"

.Fa "int permset"

.Fa "int tag"

.Fa "int qualifier"

.Fa "const wchar_t *name"

.Fc

.Ft void

.Fn archive_entry_acl_clear "struct archive_entry *a"

.Ft int

.Fn archive_entry_acl_count "struct archive_entry *a" "int type"

.Ft int

.Fo archive_entry_acl_from_text

.Fa "struct archive_entry *a"

.Fa "const char *text"

.Fa "int type"

.Fc

.Ft int

.Fo archive_entry_acl_from_text_w

.Fa "struct archive_entry *a"

.Fa "const wchar_t *text"

.Fa "int type"

.Fc

.Ft int

.Fo archive_entry_acl_next

.Fa "struct archive_entry *a"

.Fa "int type"

.Fa "int *ret_type"

.Fa "int *ret_permset"

.Fa "int *ret_tag"

.Fa "int *ret_qual"

.Fa "const char **ret_name"

.Fc

.Ft int

.Fo archive_entry_acl_next_w

.Fa "struct archive_entry *a"

.Fa "int type"

.Fa "int *ret_type"

.Fa "int *ret_permset"

.Fa "int *ret_tag"

.Fa "int *ret_qual"

.Fa "const wchar_t **ret_name"

.Fc

.Ft int

.Fn archive_entry_acl_reset "struct archive_entry *a" "int type"

.Ft char *

.Fo archive_entry_acl_to_text

.Fa "struct archive_entry *a"

.Fa "ssize_t *len_p"

.Fa "int flags"

.Fc

.Ft wchar_t *

.Fo archive_entry_acl_to_text_w

.Fa "struct archive_entry *a"

.Fa "ssize_t *len_p"

.Fa "int flags"

.Fc

.Ft int

.Fn archive_entry_acl_types "struct archive_entry *a"

.\" enum?

.Sh DESCRIPTION

The

.Dq Access Control Lists (ACLs)

extend the standard Unix perssion model.

The ACL interface of

.Nm 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.

.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

.Fa permset

are:

.Bl -tag -offset indent -compact -width "ARCHIVE_ENTRY_ACL_EXECUTE"

.It Dv ARCHIVE_ENTRY_ACL_READ ( Sy r )

.It Dv ARCHIVE_ENTRY_ACL_WRITE ( Sy w )

.It Dv ARCHIVE_ENTRY_ACL_EXECUTE ( Sy x )

.El

The permissions correspond to the normal Unix permissions.

.Pp

The

.Fa tag

specifies the principal to which the permission applies.

Valid values are:

.Bl -hang -offset indent -compact -width "ARCHIVE_ENTRY_ACL_GROUP_OBJ"

.It Dv ARCHIVE_ENTRY_ACL_USER

The user specified by the name field.

.It Dv ARCHIVE_ENTRY_ACL_USER_OBJ

The owner of the file.

.It Dv ARCHIVE_ENTRY_ACL_GROUP

The group specied by the name field.

.It Dv ARCHIVE_ENTRY_ACL_GROUP_OBJ

The group who owns the file.

.It Dv ARCHIVE_ENTRY_ACL_MASK

The maximum permissions to be obtained via group permissions.

.It Dv ARCHIVE_ENTRY_ACL_OTHER

Any principal who is not file owner or a member of the owning group.

.El

.Pp

The principals

.Dv ARCHIVE_ENTRY_ACL_USER_OBJ ,

.Dv ARCHIVE_ENTRY_ACL_GROUP_OBJ

and

.Dv 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

.Pq Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS .

This specifies the permissions required for access to the file itself.

Directories have an additional ACL

.Pq Dv 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:

.Bl -hang -offset indent -compact -width "ARCHIVE_ENTRY_ACL_TYE_ALLOW"

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ALLOW

Allow principal to perform actions requiring given permissions.

.It Dv ARCHIVE_ENTRY_ACL_TYPE_DENY

Prevent principal from performing actions requiring given permissions.

.It Dv ARCHIVE_ENTRY_ACL_TYPE_AUDIT

Log access attempts by principal which require given permissions.

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ALARM

Trigger a system alarm on access attempts by principal which require given

permissions.

.El

.Pp

The

.Fa tag

specifies the principal to which the permission applies.

Valid values are:

.Bl -hang -offset indent -compact -width "ARCHIVE_ENTRY_ACL_GROUP_OBJ"

.It Dv ARCHIVE_ENTRY_ACL_USER

The user specified by the name field.

.It Dv ARCHIVE_ENTRY_ACL_USER_OBJ

The owner of the file.

.It Dv ARCHIVE_ENTRY_ACL_GROUP

The group specied by the name field.

.It Dv ARCHIVE_ENTRY_ACL_GROUP_OBJ

The group who owns the file.

.It Dv ARCHIVE_ENTRY_ACL_EVERYONE

Any principal who is not file owner or a member of the owning group.

.El

.Pp

Entries with the

.Dv ARCHIVE_ENTRY_ACL_USER

or

.Dv ARCHIVE_ENTRY_ACL_GROUP

tag store the user and group name in the

.Fa name

string and optionally the user or group ID in the

.Fa qualifier

integer.

.Pp

NFSv4 ACE permissions and flags are stored in the same

.Fa 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:

.Bl -tag -offset indent -compact -width ARCHIV

.It Dv ARCHIVE_ENTRY_ACL_READ_DATA ( Sy r )

Read data (file).

.It Dv ARCHIVE_ENTRY_ACL_LIST_DIRECTORY ( Sy r )

List entries (directory).

.It ARCHIVE_ENTRY_ACL_WRITE_DATA ( Sy w )

Write data (file).

.It ARCHIVE_ENTRY_ACL_ADD_FILE ( Sy w )

Create files (directory).

.It Dv ARCHIVE_ENTRY_ACL_EXECUTE ( Sy x )

Execute file or change into a directory.

.It Dv ARCHIVE_ENTRY_ACL_APPEND_DATA ( Sy p )

Append data (file).

.It Dv ARCHIVE_ENTRY_ACL_ADD_SUBDIRECTORY ( Sy p )

Create subdirectories (directory).

.It Dv ARCHIVE_ENTRY_ACL_DELETE_CHILD ( Sy D )

Remove files and subdirectories inside a directory.

.It Dv ARCHIVE_ENTRY_ACL_DELETE ( Sy d )

Remove file or directory.

.It Dv ARCHIVE_ENTRY_ACL_READ_ATTRIBUTES ( Sy a )

Read file or directory attributes.

.It Dv ARCHIVE_ENTRY_ACL_WRITE_ATTRIBUTES ( Sy A )

Write file or directory attributes.

.It Dv ARCHIVE_ENTRY_ACL_READ_NAMED_ATTRS ( Sy R )

Read named file or directory attributes.

.It Dv ARCHIVE_ENTRY_ACL_WRITE_NAMED_ATTRS ( Sy W )

Write named file or directory attributes.

.It Dv ARCHIVE_ENTRY_ACL_READ_ACL ( Sy c )

Read file or directory ACL.

.It Dv ARCHIVE_ENTRY_ACL_WRITE_ACL ( Sy C )

Write file or directory ACL.

.It Dv ARCHIVE_ENTRY_ACL_WRITE_OWNER ( Sy o )

Change owner of a file or directory.

.It Dv ARCHIVE_ENTRY_ACL_SYNCHRONIZE ( Sy s )

Use synchronous I/O.

.El

.Pp

The following NFSv4 ACL inheritance flags are supported:

.Bl -tag -offset indent -compact -width ARCHIV

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_FILE_INHERIT ( Sy f )

Inherit parent directory ACE to files.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_DIRECTORY_INHERIT ( Sy d )

Inherit parent directory ACE to subdirectories.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_INHERIT_ONLY ( Sy i )

Only inherit, do not apply the permission on the directory itself.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_NO_PROPAGATE_INHERIT ( Sy n )

Do not propagate inherit flags. Only first-level entries inherit ACLs.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_SUCCESSFUL_ACCESS ( Sy S )

Trigger alarm or audit on successful access.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_FAILED_ACCESS ( Sy F )

Trigger alarm or audit on failed access.

.It Dv ARCHIVE_ENTRY_ACL_ENTRY_INHERITED ( Sy I )

Mark that ACE was inherited.

.El

.Ss Functions

.Fn archive_entry_acl_add_entry

and

.Fn 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.

.Pp

.Fn archive_entry_acl_clear

removes all ACL entries and resets the enumeration pointer.

.Pp

.Fn archive_entry_acl_count

counts the ACL entries that have the given type mask.

.Fa type

can be the bitwise-or of

.Bl -tag -offset indent -compact -width "ARCHIVE_ENTRY_ACL_TYPE_DEFAULT"

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

.It Dv ARCHIVE_ENTRY_ACL_TYPE_DEFAULT

.El

for POSIX.1e ACLs and

.Bl -tag -offset indent -compact -width "ARCHIVE_ENTRY_ACL_TYPE_ALLOW"

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ALLOW

.It Dv ARCHIVE_ENTRY_ACL_TYPE_DENY

.It Dv ARCHIVE_ENTRY_ACL_TYPE_AUDIT

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ALARM

.El

for NFSv4 ACLs. For POSIX.1e ACLs if

.Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

is included and at least one extended ACL entry is found,

the three non-extended ACLs are added.

.Pp

.Fn archive_entry_acl_from_text

and

.Fn archive_entry_acl_from_text_w

add new

.Pq or merge with existing

ACL entries from

.Pq wide

text. The argument

.Fa type

may take one of the following values:

.Bl -tag -offset indent -compact -width "ARCHIVE_ENTRY_ACL_TYPE_DEFAULT"

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

.It Dv ARCHIVE_ENTRY_ACL_TYPE_DEFAULT

.It Dv ARCHIVE_ENTRY_ACL_TYPE_NFS4

.El

Supports all formats that can be created with

.Fn archive_entry_acl_to_text

or respective

.Fn archive_entry_acl_to_text_w .

Existing ACL entries are preserved. To get a clean new ACL from text

.Fn archive_entry_acl_clear

must be called first. Entries prefixed with

.Dq default:

are treated as

.Dv ARCHIVE_ENTRY_ACL_TYPE_DEFAULT

unless

.Fa type

is

.Dv ARCHIVE_ENTRY_ACL_TYPE_NFS4 .

Invalid entries, non-parseable ACL entries and entries beginning with

the

.Sq #

character

.Pq comments

are skipped.

.Pp

.Fn archive_entry_acl_next

and

.Fn archive_entry_acl_next_w

return the next entry of the ACL list.

This functions may only be called after

.Fn archive_entry_acl_reset

has indicated the presence of extended ACL entries.

.Pp

.Fn archive_entry_acl_reset

prepare reading the list of ACL entries with

.Fn archive_entry_acl_next

or

.Fn archive_entry_acl_next_w .

The function returns either 0, if no non-extended ACLs are found.

In this case, the access permissions should be obtained by

.Xr archive_entry_mode 3

or set using

.Xr chmod 2 .

Otherwise, the function returns the same value as

.Fn archive_entry_acl_count .

.Pp

.Fn archive_entry_acl_to_text

and

.Fn archive_entry_acl_to_text_w

convert the ACL entries for the given type into a

.Pq wide

string of ACL entries separated by newline. If the pointer

.Fa len_p

is not NULL, then the function shall return the length of the string

.Pq not including the NULL terminator

in the location pointed to by

.Fa len_p .

The

.Fa flag

argument is a bitwise-or.

.Pp

The following flags are effective only on POSIX.1e ACL:

.Bl -tag -offset indent -compact -width ARCHIV

.It Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

Output access ACLs.

.It Dv ARCHIVE_ENTRY_ACL_TYPE_DEFAULT

Output POSIX.1e default ACLs.

.It Dv ARCHIVE_ENTRY_ACL_STYLE_MARK_DEFAULT

Prefix each default ACL entry with the word

.Dq default: .

.It Dv ARCHIVE_ENTRY_ACL_STYLE_SOLARIS

The mask and other ACLs don not contain a double colon.

.El

.Pp

The following flags are effecive only on NFSv4 ACL:

.Bl -tag -offset indent -compact -width ARCHIV

.It Dv ARCHIVE_ENTRY_ACL_STYLE_COMPACT

Do not output minus characters for unset permissions and flags in NFSv4 ACL

permission and flag fields.

.El

.Pp

The following flags are effective on both POSIX.1e and NFSv4 ACL:

.Bl -tag -offset indent -compact -width ARCHIV

.It Dv ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID

Add an additional colon-separated field containing the user or group id.

.It Dv ARCHIVE_ENTRY_ACL_STYLE_SEPARATOR_COMMA

Separate ACL entries with comma instead of newline.

.El

.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

.Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

or

.Dv ARCHIVE_ENTRY_ACL_TYPE_DEFAULT

are specified, both access and default entries are returned and default entries

are prefixed with

.Dq default: .

.Pp

.Fn archive_entry_acl_types

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

.Fn archive_entry_acl_count

and

.Fn 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

.Dv ARCHIVE_ENTRY_ACL_TYPE_ACCESS

and at least one extended ACL entry exists, the three classic Unix

permissions are counted.

.Pp

.Fn archive_entry_acl_from_text

and

.Fn archive_entry_acl_from_text_w

return

.Dv ARCHIVE_OK

if all entries were successfully parsed and

.Dv ARCHIVE_WARN

if one or more entries were invalid or non-parseable.

.Pp

.Fn archive_entry_acl_next

and

.Fn archive_entry_acl_next_w

return

.Dv ARCHIVE_OK

on success,

.Dv ARCHIVE_EOF

if no more ACL entries exist

and

.Dv ARCHIVE_WARN

if

.Fn archive_entry_acl_reset

has not been called first.

.Pp

.Fn archive_entry_acl_to_text

returns a string representing the ACL entries matching the given type and

flags on success or NULL on error.

.Pp

.Fn 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.

.Pp

.Fn archive_entry_acl_types

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

.Sh SEE ALSO

.Xr archive_entry 3 ,

.Xr libarchive 3