mgw_nat/src/imsi_list.erl

80 lines
2.1 KiB
Erlang

% Maintain a list of IMSIs in a gb_tree and match against it
% (C) 2012 by Harald Welte <laforge@gnumonks.org>
% (C) 2012 by On-Waves
%
% All Rights Reserved
%
% 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.
%
% 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.
%
% You should have received a copy of the GNU General Public License along
% with this program; if not, write to the Free Software Foundation, Inc.,
% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-module(imsi_list).
-author('Harald Welte <laforge@gnumonks.org>').
-export([read_file/1, read_list/1, match_imsi/2]).
lines2tree(Iodev) ->
lines2tree(Iodev, gb_trees:empty()).
chomp(Line) when is_list(Line) ->
case lists:last(Line) of
10 ->
lists:sublist(Line, 1, length(Line)-1);
_ ->
Line
end.
lines2tree(Iodev, Tree) ->
case file:read_line(Iodev) of
eof ->
{ok, Tree};
{error, Reason} ->
{error, Reason};
ebadf ->
{error, ebadf};
{ok, Line} ->
% FIXME: convert to digit list
Line2 = chomp(Line),
Line3 = [case string:to_integer([X]) of {Int,[]} -> Int end || X <- Line2],
lines2tree(Iodev, gb_trees:insert(Line3, true, Tree))
end.
read_file(FileName) ->
% read a text file with one IMSI per line into a gb_tree
case file:open(FileName, [read]) of
{ok, IoDev} ->
lines2tree(IoDev);
{error, Reason} ->
{error, Reason}
end.
read_list(List) when is_list(List) ->
read_list(List, gb_trees:empty()).
read_list([], Tree) ->
Tree;
read_list([Head|Tail], Tree) ->
read_list(Tail, gb_trees:enter(Head, true, Tree)).
match_imsi(Tree, Imsi) when is_list(Imsi) ->
case gb_trees:lookup(Imsi, Tree) of
{value, true} ->
true;
{value, _} ->
false;
none ->
false
end.