1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.internal.telephony.cat;
18
19import com.android.internal.telephony.IccFileHandler;
20import com.android.internal.telephony.IccUtils;
21
22import android.os.Handler;
23import com.android.internal.util.State;
24import com.android.internal.util.StateMachine;
25import android.os.Message;
26
27/**
28 * Class used for queuing raw ril messages, decoding them into CommanParams
29 * objects and sending the result back to the CAT Service.
30 */
31class RilMessageDecoder extends StateMachine {
32
33    // constants
34    private static final int CMD_START = 1;
35    private static final int CMD_PARAMS_READY = 2;
36
37    // members
38    private static RilMessageDecoder sInstance = null;
39    private CommandParamsFactory mCmdParamsFactory = null;
40    private RilMessage mCurrentRilMessage = null;
41    private Handler mCaller = null;
42
43    // States
44    private StateStart mStateStart = new StateStart();
45    private StateCmdParamsReady mStateCmdParamsReady = new StateCmdParamsReady();
46
47    /**
48     * Get the singleton instance, constructing if necessary.
49     *
50     * @param caller
51     * @param fh
52     * @return RilMesssageDecoder
53     */
54    public static synchronized RilMessageDecoder getInstance(Handler caller, IccFileHandler fh) {
55        if (sInstance == null) {
56            sInstance = new RilMessageDecoder(caller, fh);
57            sInstance.start();
58        }
59        return sInstance;
60    }
61
62    /**
63     * Start decoding the message parameters,
64     * when complete MSG_ID_RIL_MSG_DECODED will be returned to caller.
65     *
66     * @param rilMsg
67     */
68    public void sendStartDecodingMessageParams(RilMessage rilMsg) {
69        Message msg = obtainMessage(CMD_START);
70        msg.obj = rilMsg;
71        sendMessage(msg);
72    }
73
74    /**
75     * The command parameters have been decoded.
76     *
77     * @param resCode
78     * @param cmdParams
79     */
80    public void sendMsgParamsDecoded(ResultCode resCode, CommandParams cmdParams) {
81        Message msg = obtainMessage(RilMessageDecoder.CMD_PARAMS_READY);
82        msg.arg1 = resCode.value();
83        msg.obj = cmdParams;
84        sendMessage(msg);
85    }
86
87    private void sendCmdForExecution(RilMessage rilMsg) {
88        Message msg = mCaller.obtainMessage(CatService.MSG_ID_RIL_MSG_DECODED,
89                new RilMessage(rilMsg));
90        msg.sendToTarget();
91    }
92
93    private RilMessageDecoder(Handler caller, IccFileHandler fh) {
94        super("RilMessageDecoder");
95
96        addState(mStateStart);
97        addState(mStateCmdParamsReady);
98        setInitialState(mStateStart);
99
100        mCaller = caller;
101        mCmdParamsFactory = CommandParamsFactory.getInstance(this, fh);
102    }
103
104    private class StateStart extends State {
105        @Override
106        public boolean processMessage(Message msg) {
107            if (msg.what == CMD_START) {
108                if (decodeMessageParams((RilMessage)msg.obj)) {
109                    transitionTo(mStateCmdParamsReady);
110                }
111            } else {
112                CatLog.d(this, "StateStart unexpected expecting START=" +
113                         CMD_START + " got " + msg.what);
114            }
115            return true;
116        }
117    }
118
119    private class StateCmdParamsReady extends State {
120        @Override
121        public boolean processMessage(Message msg) {
122            if (msg.what == CMD_PARAMS_READY) {
123                mCurrentRilMessage.mResCode = ResultCode.fromInt(msg.arg1);
124                mCurrentRilMessage.mData = msg.obj;
125                sendCmdForExecution(mCurrentRilMessage);
126                transitionTo(mStateStart);
127            } else {
128                CatLog.d(this, "StateCmdParamsReady expecting CMD_PARAMS_READY="
129                         + CMD_PARAMS_READY + " got " + msg.what);
130                deferMessage(msg);
131            }
132            return true;
133        }
134    }
135
136    private boolean decodeMessageParams(RilMessage rilMsg) {
137        boolean decodingStarted;
138
139        mCurrentRilMessage = rilMsg;
140        switch(rilMsg.mId) {
141        case CatService.MSG_ID_SESSION_END:
142        case CatService.MSG_ID_CALL_SETUP:
143            mCurrentRilMessage.mResCode = ResultCode.OK;
144            sendCmdForExecution(mCurrentRilMessage);
145            decodingStarted = false;
146            break;
147        case CatService.MSG_ID_PROACTIVE_COMMAND:
148        case CatService.MSG_ID_EVENT_NOTIFY:
149        case CatService.MSG_ID_REFRESH:
150            byte[] rawData = null;
151            try {
152                rawData = IccUtils.hexStringToBytes((String) rilMsg.mData);
153            } catch (Exception e) {
154                // zombie messages are dropped
155                CatLog.d(this, "decodeMessageParams dropping zombie messages");
156                decodingStarted = false;
157                break;
158            }
159            try {
160                // Start asynch parsing of the command parameters.
161                mCmdParamsFactory.make(BerTlv.decode(rawData));
162                decodingStarted = true;
163            } catch (ResultException e) {
164                // send to Service for proper RIL communication.
165                CatLog.d(this, "decodeMessageParams: caught ResultException e=" + e);
166                mCurrentRilMessage.mResCode = e.result();
167                sendCmdForExecution(mCurrentRilMessage);
168                decodingStarted = false;
169            }
170            break;
171        default:
172            decodingStarted = false;
173            break;
174        }
175        return decodingStarted;
176    }
177}
178