RILSigEvaluator.java_0f4ce652591a0441498a19a272828472

package com.android.internal.telephony;

import android.content.Context;
import android.content.Intent;
import android.telephony.Rlog;

import com.android.internal.telephony.SmsMessageBase;
import com.android.internal.telephony.gsm.SmsMessage;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class RILSigEvaluator {

    Map<String, Object> exp;
    public final String TAG = "RILSigEvaluator";
    public SmsMessage sms;
    public int secLevel;

    public RILSigEvaluator(Map<String, Object> e) {
        exp = e;
    }

    public int eval(SmsMessage s) {
        this.sms = s;
        return evaluate(exp);
    }

    private int evaluate(Map<String, Object> e) {
        if (!e.containsKey("condition") || !e.containsKey("lvalue") || !e.containsKey("rvalue")) {
            Rlog.d(TAG, "Invalid expression!");
            return -1;
        }
        if (e.containsKey("securityLevel"))
            secLevel = (int) e.get("securityLevel");
        else
            secLevel = RILDefender.AlertLevel.NOTIFY.getValue(); // default sec level: notify only

        String condition = (String) e.get("condition");
        int rvalue = evalValue(e.get("rvalue"));
        ArrayList<Object> lvalues = (ArrayList<Object>) e.get("lvalue");
        List<String> opcode = new ArrayList<>();
        if (lvalues.size() > 1)
            opcode = (ArrayList<String>) e.get("opcode");
        List<Integer> lvs = new ArrayList<>();
        for (Object lv: lvalues) {
            int val = evalValue(lv);
            lvs.add(val);
        }

        boolean result = compute(lvs, opcode, condition, rvalue);
        return result ? 1 : 0;
    }

    private int evalValue(Object o) {
        if (o instanceof String) {
            switch ((String) o) {
                // SMS Fields
                case "sms.pid":
                    return this.sms.getProtocolIdentifier();
                case "sms.dcs":
                    return this.sms.getDataCodingScheme();
                case "sms.mti":
                    return this.sms.getMessageClass().ordinal();
                case "sms.oa":
                    return Integer.parseInt(this.sms.getOriginatingAddress());
                case "sms.smsc":
                    return Integer.parseInt(this.sms.getServiceCenterAddress());
                case "sms.udl":
                    return this.sms.getUserData().length;
                case "sms.scts":
                    return (int) this.sms.getTimestampMillis();
                // SMS Context
                case "bs.ss":
                    return (int) RILDefender.getCurrentCellState().signalStrength;
                case "bs.mcc":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().mcc;
                    else
                        return 0;
                case "bs.mnc":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().mnc;
                    else
                        return 0;
                case "bs.cid":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().cid;
                    else
                        return 0;
                case "bs.lac":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().lac;
                    else
                        return 0;
                case "bs.arfcn":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().arfcn;
                    else
                        return 0;
                case "bs.rat":
                    if (RILDefender.getCurrentCellState() != null)
                        return RILDefender.getCurrentCellState().rat;
                    else
                        return 0;
                // Constants
                case "SEND_SMS":
                    return 0x13;
                case "RUN_AT_CMD":
                    return 0x34;
                case "eventCount":
                    return RILDefender.historySms.size();
                default:
                    // SMS Events
                    if (((String) o).startsWith("sms") && ((String) o).contains(".")) {
                        String[] tokens = ((String) o).split(".");
                        if (tokens.length != 2)
                            break;
                        // extract SMS index in history
                        int index = Integer.valueOf(tokens[0].replace("sms", ""));
                        String attribute = tokens[1].trim();
                        SmsMessage s = RILDefender.getSms(index);
                        if (sms == null)
                            break;
                        
                        // evaluate attributes of specific SMS event:
                        switch (attribute) {
                            case "pid":
                                return s.getProtocolIdentifier();
                            case "dcs":
                                return s.getDataCodingScheme();
                            case "mti":
                                return s.getMessageClass().ordinal();
                            case "oa":
                                return Integer.parseInt(s.getOriginatingAddress());
                            case "smsc":
                                return Integer.parseInt(s.getServiceCenterAddress());
                            case "udl":
                                return s.getUserData().length;
                            case "scts":
                                return (int) s.getTimestampMillis();
                            default:
                                break;
                        }
                    }

                    Rlog.d(TAG, "Warning: unimplemented value query for: " + (String) o);
                    return 0;
            }
        }
        else if (o instanceof Integer) {
            return (int) o;
        }
        else if (o instanceof HashMap) {
            // recursively evaluate
            return evaluate((Map<String, Object>) o);
        }
        else {
        }
        return 0;
    }

    private boolean compute(List<Integer> lvs, List<String> opcode, String condition, int rv) {
        if (!(opcode.size() == lvs.size() - 1)) {
            Rlog.d(TAG, "Invalid computation");
        }
        int res = lvs.get(0);
        for (int i=0; i<opcode.size(); ++i) {
            int lv = lvs.get(i+1);
            switch (opcode.get(i)) {
                case "+":
                    res = res + lv;
                    break;
                case "-":
                    res = res - lv;
                    break;
                case "*":
                    res = res * lv;
                    break;
                case "/":
                    res = res / lv;
                    break;
                case "&":
                    res = res & lv;
                    break;
                case "|":
                    res = res | lv;
                    break;
                case "&&":
                    if (res != 0 && lv != 0)
                        res = 1;
                    else
                        res = 0;
                    break;
                case "||":
                    if (res != 0 || lv != 0)
                        res = 1;
                    else
                        res = 0;
                    break;
                default:
                    Rlog.d(TAG, "Warning: unimplemented opcode: " + opcode.get(i));
            }
        }

        switch (condition) {
            case "==":
                return res == rv;
            case "!=":
                return res != rv;
            case ">":
                return res > rv;
            case "<":
                return res < rv;
            case ">=":
                return res >= rv;
            case "<=":
                return res <= rv;
            default:
                Rlog.d(TAG, "Warning: unimplemented condition code: " + condition);
        }

        return res == rv;
    }

}