Harald Welte | fa8ada0 | 2012-01-16 15:59:45 +0100 | [diff] [blame] | 1 | % MTP3 Signalling Link Test Control (SLTC) according to Q.707 |
| 2 | |
| 3 | % (C) 2011-2012 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(mtp3_sltc). |
| 21 | -author('Harald Welte <laforge@gnumonks.org>'). |
| 22 | -behaviour(gen_fsm). |
| 23 | |
| 24 | -include("mtp3.hrl"). |
| 25 | |
| 26 | % gen_fsm exports |
| 27 | -export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]). |
| 28 | |
| 29 | % individual FSM states |
| 30 | -export([idle/2, first_attempt/2, second_attempt/2]). |
| 31 | |
| 32 | -record(sltc_state, { |
| 33 | hmrt_pid, |
| 34 | mgmt_pid, |
| 35 | lsac_pid, |
| 36 | sls, |
| 37 | opc, |
| 38 | adj_dpc, |
| 39 | t1, |
| 40 | t1_timeout, |
| 41 | x |
| 42 | }). |
| 43 | |
| 44 | -define(SLTC_T1_DEF, 10000). |
| 45 | -define(SLTC_T2_DEF, 60000). |
| 46 | |
| 47 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 48 | % gen_fsm callbacks |
| 49 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 50 | |
| 51 | init([Hmrt, Mgmt, Lsac, Sls, AdjDpc, Opc]) when |
| 52 | is_pid(Hmrt), is_pid(Mgmt), is_pid(Lsac), is_integer(Sls) -> |
| 53 | SltState = #sltc_state{hmrt_pid = Hmrt, |
| 54 | mgmt_pid = Mgmt, |
| 55 | lsac_pid = Lsac, |
| 56 | sls = Sls, |
| 57 | adj_dpc = AdjDpc, |
| 58 | opc = Opc, |
| 59 | t1_timeout = ?SLTC_T1_DEF, |
| 60 | x = 16#2342}, |
| 61 | {ok, idle, SltState}. |
| 62 | |
| 63 | terminate(Reason, State, _LoopDat) -> |
| 64 | io:format("Terminating ~p in State ~p (Reason: ~p)~n", |
| 65 | [?MODULE, State, Reason]), |
| 66 | ok. |
| 67 | |
| 68 | code_change(_OldVsn, StateName, LoopDat, _Extra) -> |
| 69 | {ok, StateName, LoopDat}. |
| 70 | |
| 71 | handle_event(Event, State, LoopDat) -> |
| 72 | io:format("Unknown Event ~p in state ~p~n", [Event, State]), |
| 73 | {next_state, State, LoopDat}. |
| 74 | |
| 75 | handle_info(Info, State, LoopDat) -> |
| 76 | io:format("Unknown Info ~p in state ~p~n", [Info, State]), |
| 77 | {next_state, State, LoopDat}. |
| 78 | |
| 79 | % See Figure 2 of Q.707 |
| 80 | |
| 81 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 82 | % STATE: idle |
| 83 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 84 | |
| 85 | idle(M=#mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 86 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 87 | h1 = ?MTP3MG_H1_SLTM}}, LoopDat) -> |
| 88 | Slta = slta_from_sltm(M), |
| 89 | send_to(hmrt, Slta, LoopDat), |
| 90 | {next_state, idle, LoopDat}; |
| 91 | |
| 92 | idle(start, LoopDat) -> |
| 93 | Sltm = generate_sltm(LoopDat), |
| 94 | send_to(hmrt, Sltm, LoopDat), |
| 95 | {ok, T1} = timer:apply_after(gen_fsm, send_event, |
| 96 | [self(), {timer_expired, t1}]), |
| 97 | {next_state, first_attempt, LoopDat#sltc_state{t1 = T1}}. |
| 98 | |
| 99 | |
| 100 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 101 | % STATE: first_attempt |
| 102 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 103 | |
| 104 | first_attempt(M=#mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 105 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 106 | h1 = ?MTP3MG_H1_SLTM}}, LoopDat) -> |
| 107 | Slta = slta_from_sltm(M), |
| 108 | send_to(hmrt, Slta, LoopDat), |
| 109 | {next_state, first_attempt, LoopDat}; |
| 110 | |
| 111 | first_attempt(M = #mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 112 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 113 | h1 = ?MTP3MG_H1_SLTA}}, LoopDat) -> |
| 114 | timer:cancel(LoopDat#sltc_state.t1), |
| 115 | case slt_matches(M, LoopDat) of |
| 116 | true -> |
| 117 | send_to(lsac, slt_successful, LoopDat), |
| 118 | {next_state, idle, LoopDat}; |
| 119 | false -> |
| 120 | Sltm = generate_sltm(LoopDat), |
| 121 | send_to(hmrt, Sltm, LoopDat), |
| 122 | {ok, T1} = timer:apply_after(gen_fsm, send_event, |
| 123 | [self(), {timer_expired, t1}]), |
| 124 | {next_state, second_attempt, LoopDat#sltc_state{t1 = T1}} |
| 125 | end. |
| 126 | |
| 127 | |
| 128 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 129 | % STATE: second_attempt |
| 130 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 131 | |
| 132 | second_attempt(M=#mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 133 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 134 | h1 = ?MTP3MG_H1_SLTM}}, LoopDat) -> |
| 135 | Slta = slta_from_sltm(M), |
| 136 | send_to(hmrt, Slta, LoopDat), |
| 137 | {next_state, second_attempt, LoopDat}; |
| 138 | |
| 139 | second_attempt(M = #mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 140 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 141 | h1 = ?MTP3MG_H1_SLTA}}, LoopDat) -> |
| 142 | timer:cancel(LoopDat#sltc_state.t1), |
| 143 | case slt_matches(M, LoopDat) of |
| 144 | true -> |
| 145 | send_to(lsac, slt_successful, LoopDat); |
| 146 | false -> |
| 147 | send_to(mgmt, slt_failed, LoopDat), |
| 148 | send_to(lsac, slt_failed, LoopDat) |
| 149 | end, |
| 150 | {next_state, idle, LoopDat}; |
| 151 | |
| 152 | second_attempt({timer_expired, t1}, LoopDat) -> |
| 153 | send_to(mgmt, slt_failed, LoopDat), |
| 154 | send_to(lsac, slt_failed, LoopDat), |
| 155 | {next_state, idle, LoopDat}. |
| 156 | |
| 157 | |
| 158 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 159 | % helper functions |
| 160 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 161 | send_to(hmrt, What, #sltc_state{hmrt_pid = Txc}) -> |
| 162 | Txc ! {sltc_hmrt, What}; |
| 163 | send_to(mgmt, What, #sltc_state{mgmt_pid = Txc}) -> |
| 164 | Txc ! {sltc_mgmt, What}; |
| 165 | send_to(lsac, What, #sltc_state{lsac_pid = Txc}) -> |
| 166 | Txc ! {sltc_lsac, What}. |
| 167 | |
| 168 | slta_from_sltm(M = #mtp3_msg{service_ind = ?MTP3_SERV_MGMT, |
| 169 | routing_label = RoutLbl, |
| 170 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 171 | h1 = ?MTP3MG_H1_SLTM, |
| 172 | test_pattern = TP}}) -> |
| 173 | InvRoutLbl = invert_rout_lbl(RoutLbl), |
| 174 | M#mtp3_msg{routing_label = InvRoutLbl, |
| 175 | payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, |
| 176 | h1 = ?MTP3MG_H1_SLTA, |
| 177 | test_pattern = TP}}. |
| 178 | |
| 179 | generate_sltm(LoopDat) -> |
| 180 | Mg = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST, h1 = ?MTP3MG_H1_SLTM, |
| 181 | test_pattern = LoopDat#sltc_state.x}, |
| 182 | Lbl = #mtp3_routing_label{sig_link_sel = LoopDat#sltc_state.sls, |
| 183 | origin_pc = LoopDat#sltc_state.opc, |
| 184 | dest_pc = LoopDat#sltc_state.adj_dpc}, |
| 185 | |
| 186 | #mtp3_msg{network_ind = ?MTP3_NETIND_INTERNATIONAL, |
| 187 | service_ind = ?MTP3_SERV_MGMT, |
| 188 | routing_label = Lbl, payload = Mg}. |
| 189 | |
| 190 | rout_lbl_matches(#mtp3_routing_label{sig_link_sel = SlsLocal, |
| 191 | origin_pc = OPC}, LoopDat) -> |
| 192 | #sltc_state{adj_dpc = AdjDpc, sls = SLS} = LoopDat, |
| 193 | if SLS == SlsLocal, OPC == AdjDpc -> |
| 194 | true; |
| 195 | true -> |
| 196 | false |
| 197 | end. |
| 198 | |
| 199 | slt_matches(#mtp3_msg{routing_label = RoutLbl, |
| 200 | payload = #mtp3mg_msg{test_pattern = TP}}, LoopDat) -> |
| 201 | case LoopDat#sltc_state.x of |
| 202 | TP -> |
| 203 | rout_lbl_matches(RoutLbl, LoopDat); |
| 204 | _ -> |
| 205 | false |
| 206 | end. |
| 207 | |
| 208 | |
| 209 | |
| 210 | invert_rout_lbl(L = #mtp3_routing_label{origin_pc = Opc, dest_pc = Dpc}) -> |
| 211 | L#mtp3_routing_label{origin_pc = Dpc, dest_pc = Opc}. |