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authorHarald Welte <laforge@gnumonks.org>2011-04-02 14:33:31 +0200
committerHarald Welte <laforge@gnumonks.org>2011-04-02 14:33:31 +0200
commit1f47f67d559878da4e424af5a09f15d43b087259 (patch)
tree4b2712e93b525376fa7221628f916e9d2eba0369 /src/osmo_ss7_gtt.erl
parent030f1091aa439a7018a25fd9765815d9c7cf773d (diff)
Add a new GTT module for GT matching + GT translation (GTT)
Diffstat (limited to 'src/osmo_ss7_gtt.erl')
-rw-r--r--src/osmo_ss7_gtt.erl118
1 files changed, 118 insertions, 0 deletions
diff --git a/src/osmo_ss7_gtt.erl b/src/osmo_ss7_gtt.erl
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+++ b/src/osmo_ss7_gtt.erl
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+% Osmocom Global Title Translation
+
+% (C) 2011 by Harald Welte <laforge@gnumonks.org>
+%
+% All Rights Reserved
+%
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU Affero General Public License as
+% published by the Free Software Foundation; either version 3 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 Affero General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+-module(osmo_ss7_gtt).
+-author('Harald Welte <laforge@gnumonks.org>').
+
+-include("sccp.hrl").
+-include("gtt.hrl").
+
+-export([global_title_match/2, apply_gtt_actions/2, execute_gtt/2]).
+
+% Match a given GT against an ordered list of {match, action} tuples
+global_title_match([], Gt) when is_record(Gt, global_title) ->
+ false;
+global_title_match([{Match, Action}|Tail], Gt) when is_record(Gt, global_title) ->
+ PhoneNumInt = osmo_util:digit_list2int(Gt#global_title.phone_number),
+ if Match#gtt_match.gt_range_from >= PhoneNumInt ->
+ % in an ordered list, we can assume that no trailing rules will match
+ false;
+ true ->
+ case single_gt_match(Match, Gt) of
+ true ->
+ Action;
+ _ ->
+ % iterate further over the list of GTT rules
+ global_title_match(Tail, Gt)
+ end
+ end.
+
+% perform matching of a given global title against a single match
+single_gt_match(Match, Gt) when is_record(Match, gtt_match), is_record(Gt, global_title) ->
+ #gtt_match{gt_range_from = RangeFrom, gt_range_to = RangeTo,
+ numbering_plan = NumPlan, nature_of_addr_ind = NatureInd,
+ dpc = Dpc, ssn = Ssn} = Match,
+ % build a list of the individual criteria that all have to match
+ SubMatchList = [{digits, {RangeFrom, RangeTo}, Gt#global_title.phone_number},
+ {numbering_plan, NumPlan, Gt#global_title.numbering_plan},
+ {nature_of_addr_ind, NatureInd, Gt#global_title.nature_of_addr_ind}],
+ gt_sub_match_list(SubMatchList).
+
+% iterate over the list of individual match criteria and call the match function
+gt_sub_match_list([]) ->
+ true;
+gt_sub_match_list([{What, MatchPart, GtPart}|SubMatchList]) ->
+ case gt_sub_match(What, MatchPart, GtPart) of
+ false ->
+ false;
+ true ->
+ gt_sub_match_list(SubMatchList)
+ end.
+
+% matching of the actual phone number digits
+gt_sub_match(digits, {DigitsFrom, DigitsTo}, GtPart) ->
+ PhoneNumInt = osmo_util:digit_list2int(GtPart),
+ if
+ PhoneNumInt >= DigitsFrom, PhoneNumInt =< DigitsTo -> true;
+ true -> false
+ end;
+% any match that is not qualified will always match
+gt_sub_match(_What, undefined, _GtPart) ->
+ true;
+% remaining default match for all other fields
+gt_sub_match(_What, MatchPart, GtPart) ->
+ if
+ MatchPart == GtPart -> true;
+ true -> false
+ end.
+
+
+% Execute a single action: Replac some digits in the GT
+gtt_action(Gt, Action) when is_record(Gt, global_title), is_record(Action, gtt_act_repl_digits) ->
+ #gtt_act_repl_digits{replace_digit_start = ReplDigStart,
+ replace_digit_end = ReplDigEnd,
+ new_digits = NewDigits} = Action,
+ GtDigitList = Gt#global_title.phone_number,
+ Header = lists:sublist(GtDigitList, 1, ReplDigStart-1),
+ Trailer = lists:sublist(GtDigitList, ReplDigEnd+1, length(GtDigitList)),
+ Gt#global_title{phone_number = Header ++ NewDigits ++ Trailer};
+
+% Execute a single action: Replac the numbering plan in the GT
+gtt_action(Gt,Action) when is_record(Gt, global_title), is_record(Action, gtt_act_repl_num_plan) ->
+ NewNumPlan = Action#gtt_act_repl_num_plan.numbering_plan,
+ Gt#global_title{numbering_plan = NewNumPlan}.
+
+% appliy a list of GTT actions to a Global Title
+apply_gtt_actions(Gt, []) when is_record(Gt, global_title) ->
+ Gt;
+apply_gtt_actions(Gt, [Head|List]) when is_record(Gt, global_title) ->
+ NewGt = gtt_action(Gt, Head),
+ apply_gtt_actions(NewGt, List);
+apply_gtt_actions(Gt, Action) when is_record(Gt, global_title) ->
+ gtt_action(Gt, Action).
+
+% Execute a complete GTT operation: matching + executing the action
+execute_gtt(Gt, RulesList) when is_record(Gt, global_title), is_list(RulesList) ->
+ case global_title_match(RulesList, Gt) of
+ false ->
+ Gt;
+ Action ->
+ apply_gtt_actions(Gt, Action)
+ end.
+