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--
-- Copyright (C) 2011, 2012 secunet Security Networks AG
-- Copyright (C) 2011, 2012 Reto Buerki <reet@codelabs.ch>
-- Copyright (C) 2011, 2012 Adrian-Ken Rueegsegger <ken@codelabs.ch>
--
-- This program is free software; you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation; either version 2 of the License, or (at your
-- option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
--
-- This program is distributed in the hope that it will be useful, but
-- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-- for more details.
--
-- As a special exception, if other files instantiate generics from this
-- unit, or you link this unit with other files to produce an
-- executable this unit does not by itself cause the resulting
-- executable to be covered by the GNU General Public License. This
-- exception does not however invalidate any other reasons why the
-- executable file might be covered by the GNU Public License.
--
package Anet.Sockets.Filters is
type Sock_Filter_Type is record
Code : Interfaces.Unsigned_16;
-- Actual filter code.
JT : Interfaces.Unsigned_8;
-- Jump true.
JF : Interfaces.Unsigned_8;
-- Jump false.
K : Interfaces.Unsigned_32;
-- Generic multiuse field.
end record;
pragma Convention (C, Sock_Filter_Type);
-- Linux Packet Filter (LPF) block (struct sock_filter).
type Sock_Filter_Array is array (Positive range <>) of Sock_Filter_Type;
-- Sock filter array.
procedure Set_Filter
(Socket : Socket_Type;
Filter : Sock_Filter_Array);
-- Apply filter on given socket.
-------------
-- Filters --
-------------
Filter_Discard_All : constant Sock_Filter_Array;
-- Filter: discard all packets.
Filter_UDP_Port_Bootpc : constant Sock_Filter_Array;
-- Filter: udp and dst port 68.
Filter_UDP_Port_Bootps : constant Sock_Filter_Array;
-- Filter: udp and dst port 67.
private
Filter_Discard_All : constant Sock_Filter_Array (1 .. 1)
:= (1 => (16#06#, 0, 0, 16#00000000#));
-- Compiled LPF filter, discard all packets.
Filter_UDP_Port_Bootpc : constant Sock_Filter_Array (1 .. 9)
:= ((16#30#, 0, 0, 16#00000009#),
(16#15#, 0, 6, 16#00000011#),
(16#28#, 0, 0, 16#00000006#),
(16#45#, 4, 0, 16#00001fff#),
(16#b1#, 0, 0, 16#00000000#),
(16#48#, 0, 0, 16#00000002#),
(16#15#, 0, 1, 16#00000044#),
(16#06#, 0, 0, 16#ffffffff#),
(16#06#, 0, 0, 16#00000000#));
-- Compiled LPF filter shamelessly stolen from busybox dhcpc.
Filter_UDP_Port_Bootps : constant Sock_Filter_Array (1 .. 9)
:= ((16#30#, 0, 0, 16#00000009#),
(16#15#, 0, 6, 16#00000011#),
(16#28#, 0, 0, 16#00000006#),
(16#45#, 4, 0, 16#00001fff#),
(16#b1#, 0, 0, 16#00000000#),
(16#48#, 0, 0, 16#00000002#),
(16#15#, 0, 1, 16#00000043#),
(16#06#, 0, 0, 16#ffffffff#),
(16#06#, 0, 0, 16#00000000#));
end Anet.Sockets.Filters;
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