path: root/app/src/fil/libre/repwifiapp/network/Engine6p0.java

//
// Copyright 2017, 2018 Filippo "Fil" Bergamo <fil.bergamo@riseup.net>
// 
// This file is part of RepWifiApp.
//
// RepWifiApp is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// RepWifiApp 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 General Public License
// along with RepWifiApp.  If not, see <http://www.gnu.org/licenses/>.
// 
// ********************************************************************

package fil.libre.repwifiapp.network;

import fil.libre.repwifiapp.Commons;
import fil.libre.repwifiapp.helpers.Logger;
import fil.libre.repwifiapp.helpers.RootCommand;
import fil.libre.repwifiapp.helpers.ShellCommand;
import org.apache.http.conn.util.InetAddressUtils;

public class Engine6p0 extends Engine {

    private Object abortFlagSync = new Object();
    private boolean abortConnectionSignaled = false;

    @Override
    public int connect(AccessPointInfo info) {

        WpaSupplicant.kill();
        

        if (info == null) {
            Logger.logDebug("Engine's connect() received a null AccessPointInfo");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // clear any previously set network
        if (!destroyNetwork()) {
            Logger.logDebug("Unable to ndc destroy network");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // clear interface's ip
        if (!clearAddrs()) {
            Logger.logDebug("Unable to ndc clearaddrs");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // bring up interface
        if (!interfaceUp()) {
            Logger.logDebug("Unable to bring up interface.");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // launch wpa_supplicant specifying our custom configuration and the
        // socket file
        if (!WpaSupplicant.start()) {
            Logger.logDebug("Unable to run wpa start");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // create new network and get network id
        String netID = WpaCli.createNetworkGetId();
        if (netID == null) {
            Logger.logDebug("Unable to fetch network id");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // set network SSID
        if (!WpaCli.setNetworkSSID(info.getSsid(), netID)) {
            Logger.logDebug("Failed to set network ssid");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        if (info.isHidden() && !WpaCli.setNetworkScanSSID(netID)) {
            Logger.logDebug("Failed to set scan_ssid 1 for hidden network.");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // set password (if any)
        if (!WpaCli.setNetworkPSK(info, netID)) {
            Logger.logDebug("Failed to set network psk");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // select the network we just created
        if (!WpaCli.selectNetwork(netID)) {
            Logger.logDebug("Unable to wpa_cli select network");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // enable the newtork
        if (!WpaCli.enableNetwork(netID)) {
            Logger.logDebug("Unable to wpa_cli enable_newtork");
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // kill previous dhchcd instances
        if (!killDhcpcd()) {
            Logger.logError("Unable to kill previous instances of dhcpcd");
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // get DHCP
        Logger.logDebug("Attempt to run dhcpcd..");
        try {

            int retcode = runDhcpcd(info.getDhcpConfiguration());
            if (retcode == 1) {
                Logger.logDebug("Dhcpcd exited on timeout exceeded.");
                return ConnectionResult.CONN_TIMEOUT;

            } else if (retcode != 0) {
                Logger.logDebug("Dhcpcd exited with unknown code: " + retcode);
                return ConnectionResult.CONN_FAILED;

            }
        } catch (Exception e) {
            Logger.logError("Exception while executing dhcpcd: ", e);
            return ConnectionResult.CONN_FAILED;
        }

        if (!checkAbortSignal())
            return ConnectionResult.CONN_ABORTED;

        // try to fetch gateway
        String gw = getGateWayTimeout(Commons.WAIT_FOR_GATEWAY);
        if (gw == null || !InetAddressUtils.isIPv4Address(gw)) {
            // failed to get gateway
            Logger.logDebug("Failed to get gateway");
            return ConnectionResult.CONN_GW_FAIL;
        }

        /*
         * Calls to ndc to set gateway and dns were removed 2018-04-09
         * Starting from 2018-04-20, RepWifi registers itself as a NetworkAgent.
         * When we register, all the following steps are performed by
         * ConnectivityService itself:
         * - creating a new network
         * - setting the gateway
         * - setting DNS
         * There is no reason to perform those actions on our side via the command line;
         * it would conflict with ConnectivityService's calls to "ndc"
         */

        return ConnectionResult.CONN_OK;

    }

    public void abortConnection() {
        synchronized (abortFlagSync) {
            this.abortConnectionSignaled = true;
        }
    }

    @Override
    public ConnectionStatus getConnectionStatus() {
        ConnectionStatus s = super.getConnectionStatus();
        if (s == null) {
            return null;
        }

        s.gateway = this.getGateway();

        return s;
    }

    private boolean checkAbortSignal() {

        synchronized (abortFlagSync) {
            if (abortConnectionSignaled) {
                abortConnectionSignaled = false;
                Logger.logDebug("Engine received abort connection signal. Aborting connection...");
                killDhcpcd();
                disconnect();
                return false;
            } else {
                return true;
            }
        }
    }

    private boolean destroyNetwork() {

        // needs root (tested)
        return RootCommand.executeRootCmd("ndc network destroy 1");
    }

    private String getGateWayTimeout(int timeoutMillis) {

        String gw = getGateway();
        if (gw != null && !gw.trim().isEmpty()) {
            return gw;
        }

        Logger.logDebug("Gateway not available.. going into wait loop..");

        // gateway not (yet) available
        // waits for a maximum of timeoutMillis milliseconds
        // to let the interface being registered.
        int msWaited = 0;
        while (msWaited < timeoutMillis) {

            try {
                Thread.sleep(100);
            } catch (Exception e) {
                return null;
            }
            msWaited += 100;

            gw = getGateway();
            if (gw != null && !gw.trim().isEmpty()) {
                Logger.logDebug("Gateway found after wait loop!");
                return gw;
            }
        }

        // unable to get gateway
        Logger.logError("Gateway not found after wait loop.");
        return null;

    }

    private String getGateway() {

        try {

            // doesn't need root (tested)
            ShellCommand cmd = new ShellCommand("ip route show dev " + WpaSupplicant.INTERFACE_NAME);
            if (cmd.execute() != 0) {
                Logger.logDebug("command failed show route");
                return null;
            }

            // read command output
            String out = cmd.getOutput();
            if (out == null) {
                return null;
            }

            String[] lines = out.split("\n");

            for (String l : lines) {

                if (l.contains("default via")) {

                    String[] f = l.split(" ");
                    if (f.length > 2) {

                        // found route's address:
                        return f[2];

                    }
                }
            }

            return null;

        } catch (Exception e) {
            Logger.logError("Error while trying to fetch route", e);
            return null;
        }

    }

    private boolean clearAddrs() {
        // needs root (tested)
        return RootCommand.executeRootCmd("ndc interface clearaddrs "
                        + WpaSupplicant.INTERFACE_NAME);
    }

}