Harald Welte | 1f47f67 | 2011-04-02 14:33:31 +0200 | [diff] [blame^] | 1 | % Osmocom Global Title Translation |
| 2 | |
| 3 | % (C) 2011 by Harald Welte <laforge@gnumonks.org> |
| 4 | % |
| 5 | % All Rights Reserved |
| 6 | % |
| 7 | % This program is free software; you can redistribute it and/or modify |
| 8 | % it under the terms of the GNU Affero General Public License as |
| 9 | % published by the Free Software Foundation; either version 3 of the |
| 10 | % License, or (at your option) any later version. |
| 11 | % |
| 12 | % This program is distributed in the hope that it will be useful, |
| 13 | % but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | % GNU General Public License for more details. |
| 16 | % |
| 17 | % You should have received a copy of the GNU Affero General Public License |
| 18 | % along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | |
| 20 | -module(osmo_ss7_gtt). |
| 21 | -author('Harald Welte <laforge@gnumonks.org>'). |
| 22 | |
| 23 | -include("sccp.hrl"). |
| 24 | -include("gtt.hrl"). |
| 25 | |
| 26 | -export([global_title_match/2, apply_gtt_actions/2, execute_gtt/2]). |
| 27 | |
| 28 | % Match a given GT against an ordered list of {match, action} tuples |
| 29 | global_title_match([], Gt) when is_record(Gt, global_title) -> |
| 30 | false; |
| 31 | global_title_match([{Match, Action}|Tail], Gt) when is_record(Gt, global_title) -> |
| 32 | PhoneNumInt = osmo_util:digit_list2int(Gt#global_title.phone_number), |
| 33 | if Match#gtt_match.gt_range_from >= PhoneNumInt -> |
| 34 | % in an ordered list, we can assume that no trailing rules will match |
| 35 | false; |
| 36 | true -> |
| 37 | case single_gt_match(Match, Gt) of |
| 38 | true -> |
| 39 | Action; |
| 40 | _ -> |
| 41 | % iterate further over the list of GTT rules |
| 42 | global_title_match(Tail, Gt) |
| 43 | end |
| 44 | end. |
| 45 | |
| 46 | % perform matching of a given global title against a single match |
| 47 | single_gt_match(Match, Gt) when is_record(Match, gtt_match), is_record(Gt, global_title) -> |
| 48 | #gtt_match{gt_range_from = RangeFrom, gt_range_to = RangeTo, |
| 49 | numbering_plan = NumPlan, nature_of_addr_ind = NatureInd, |
| 50 | dpc = Dpc, ssn = Ssn} = Match, |
| 51 | % build a list of the individual criteria that all have to match |
| 52 | SubMatchList = [{digits, {RangeFrom, RangeTo}, Gt#global_title.phone_number}, |
| 53 | {numbering_plan, NumPlan, Gt#global_title.numbering_plan}, |
| 54 | {nature_of_addr_ind, NatureInd, Gt#global_title.nature_of_addr_ind}], |
| 55 | gt_sub_match_list(SubMatchList). |
| 56 | |
| 57 | % iterate over the list of individual match criteria and call the match function |
| 58 | gt_sub_match_list([]) -> |
| 59 | true; |
| 60 | gt_sub_match_list([{What, MatchPart, GtPart}|SubMatchList]) -> |
| 61 | case gt_sub_match(What, MatchPart, GtPart) of |
| 62 | false -> |
| 63 | false; |
| 64 | true -> |
| 65 | gt_sub_match_list(SubMatchList) |
| 66 | end. |
| 67 | |
| 68 | % matching of the actual phone number digits |
| 69 | gt_sub_match(digits, {DigitsFrom, DigitsTo}, GtPart) -> |
| 70 | PhoneNumInt = osmo_util:digit_list2int(GtPart), |
| 71 | if |
| 72 | PhoneNumInt >= DigitsFrom, PhoneNumInt =< DigitsTo -> true; |
| 73 | true -> false |
| 74 | end; |
| 75 | % any match that is not qualified will always match |
| 76 | gt_sub_match(_What, undefined, _GtPart) -> |
| 77 | true; |
| 78 | % remaining default match for all other fields |
| 79 | gt_sub_match(_What, MatchPart, GtPart) -> |
| 80 | if |
| 81 | MatchPart == GtPart -> true; |
| 82 | true -> false |
| 83 | end. |
| 84 | |
| 85 | |
| 86 | % Execute a single action: Replac some digits in the GT |
| 87 | gtt_action(Gt, Action) when is_record(Gt, global_title), is_record(Action, gtt_act_repl_digits) -> |
| 88 | #gtt_act_repl_digits{replace_digit_start = ReplDigStart, |
| 89 | replace_digit_end = ReplDigEnd, |
| 90 | new_digits = NewDigits} = Action, |
| 91 | GtDigitList = Gt#global_title.phone_number, |
| 92 | Header = lists:sublist(GtDigitList, 1, ReplDigStart-1), |
| 93 | Trailer = lists:sublist(GtDigitList, ReplDigEnd+1, length(GtDigitList)), |
| 94 | Gt#global_title{phone_number = Header ++ NewDigits ++ Trailer}; |
| 95 | |
| 96 | % Execute a single action: Replac the numbering plan in the GT |
| 97 | gtt_action(Gt,Action) when is_record(Gt, global_title), is_record(Action, gtt_act_repl_num_plan) -> |
| 98 | NewNumPlan = Action#gtt_act_repl_num_plan.numbering_plan, |
| 99 | Gt#global_title{numbering_plan = NewNumPlan}. |
| 100 | |
| 101 | % appliy a list of GTT actions to a Global Title |
| 102 | apply_gtt_actions(Gt, []) when is_record(Gt, global_title) -> |
| 103 | Gt; |
| 104 | apply_gtt_actions(Gt, [Head|List]) when is_record(Gt, global_title) -> |
| 105 | NewGt = gtt_action(Gt, Head), |
| 106 | apply_gtt_actions(NewGt, List); |
| 107 | apply_gtt_actions(Gt, Action) when is_record(Gt, global_title) -> |
| 108 | gtt_action(Gt, Action). |
| 109 | |
| 110 | % Execute a complete GTT operation: matching + executing the action |
| 111 | execute_gtt(Gt, RulesList) when is_record(Gt, global_title), is_list(RulesList) -> |
| 112 | case global_title_match(RulesList, Gt) of |
| 113 | false -> |
| 114 | Gt; |
| 115 | Action -> |
| 116 | apply_gtt_actions(Gt, Action) |
| 117 | end. |
| 118 | |