(*

Module: Resolv

  Parses /etc/resolv.conf

Author: Raphael Pinson <raphink@gmail.com>

About: Reference

  This lens tries to keep as close as possible to `man resolv.conf` where possible.

About: Licence

  This file is licensed under the LGPL v2+, like the rest of Augeas.

About: Lens Usage

About: Configuration files

  This lens applies to /etc/resolv.conf. See <filter>.

*)

module Resolv =

autoload xfm

(************************************************************************

 * Group:                 USEFUL PRIMITIVES

 *************************************************************************)

(* View: comment *)

let comment = Util.comment_generic /[ \t]*[;#][ \t]*/ "# "

(* View: comment_eol *)

let comment_eol = Util.comment_generic /[ \t]*[;#][ \t]*/ " # "

(* View: empty *)

let empty = Util.empty_generic_dos /[ \t]*[#;]?[ \t]*/

(************************************************************************

 * Group:                 MAIN OPTIONS

 *************************************************************************)

(* View: netmask

A network mask for IP addresses *)

let netmask = [ label "netmask" . Util.del_str "/" . store Rx.ip ]

(* View: ipaddr

An IP address or range with an optional mask *)

let ipaddr = [label "ipaddr" . store Rx.ip . netmask?]

(* View: nameserver

     A nameserver entry *)

let nameserver = Build.key_value_line_comment

                    "nameserver" Sep.space (store Rx.ip) comment_eol

(* View: domain *)

let domain = Build.key_value_line_comment

                    "domain" Sep.space (store Rx.word) comment_eol

(* View: search *)

let search = Build.key_value_line_comment

                    "search" Sep.space

                    (Build.opt_list

                           [label "domain" . store Rx.word]

                            Sep.space)

                    comment_eol

(* View: sortlist *)

let sortlist = Build.key_value_line_comment

                    "sortlist" Sep.space

                    (Build.opt_list

                           ipaddr

                           Sep.space)

                    comment_eol

(* View: lookup *)

let lookup =

  let lookup_entry = Build.flag("bind"|"file"|"yp")

    in Build.key_value_line_comment

             "lookup" Sep.space

             (Build.opt_list

                    lookup_entry

                    Sep.space)

             comment_eol

(* View: family *)

let family =

  let family_entry = Build.flag("inet4"|"inet6")

    in Build.key_value_line_comment

             "family" Sep.space

             (Build.opt_list

                    family_entry

                    Sep.space)

             comment_eol

(************************************************************************

 * Group:                 SPECIAL OPTIONS

 *************************************************************************)

(* View: ip6_dotint

     ip6-dotint option, which supports negation *)

let ip6_dotint =

  let negate = [ del "no-" "no-" . label "negate" ]

    in [ negate? . key "ip6-dotint" ]

(* View: options

     Options values *)

let options =

      let options_entry = Build.key_value ("ndots"|"timeout"|"attempts")

                                          (Util.del_str ":") (store Rx.integer)

                        | Build.flag ("debug"|"rotate"|"no-check-names"

                                     |"inet6"|"ip6-bytestring"|"edns0"

				     |"single-request-reopen")

                        | ip6_dotint

            in Build.key_value_line_comment

                    "options" Sep.space

                    (Build.opt_list

                           options_entry

                           Sep.space)

                    comment_eol

(* View: entry *)

let entry = nameserver

          | domain

          | search

          | sortlist

          | options

          | lookup

          | family

(* View: lns *)

let lns = ( empty | comment | entry )*

(* Variable: filter *)

let filter = (incl "/etc/resolv.conf")

let xfm = transform lns filter