Getting WiFi Direct IP address of my device

Question

I am trying to get the ip address of my device but all in vain and no success. I've tried

public String getP2PIpAddr() {
       WifiManager wifiManager = (WifiManager) getSystemService(WIFI_P2P_SERVICE);
       WifiInfo wifiInfo = wifiManager.getConnectionInfo();
       int ip = wifiInfo.getIpAddress();

       String ipString = String.format(
       "%d.%d.%d.%d",
       (ip & 0xff),
       (ip >> 8 & 0xff),
       (ip >> 16 & 0xff),
       (ip >> 24 & 0xff));

       return ipString;
    }

but its giving me 0.0.0.0 and no other method is working too..Help !!

Answer 1

send out the peer's local ip address (starting with 192.168.x.x) to the group owner. After this "handshake", which doesn't really take time, it's all good to go. Did not find any other way to get the peer's ip addresses, the only information provided by GroupListener/PeerListener/... is the mac address.

Answer 2

public static String getIpAddress() {
    try {
        List<NetworkInterface> interfaces = Collections
                .list(NetworkInterface.getNetworkInterfaces());
        /*
         * for (NetworkInterface networkInterface : interfaces) { Log.v(TAG,
         * "interface name " + networkInterface.getName() + "mac = " +
         * getMACAddress(networkInterface.getName())); }
         */

        for (NetworkInterface intf : interfaces) {
            if (!getMACAddress(intf.getName()).equalsIgnoreCase(
                    Globals.thisDeviceAddress)) {
                // Log.v(TAG, "ignore the interface " + intf.getName());
                // continue;
            }
            if (!intf.getName().contains("p2p"))
                continue;

            Log.v(TAG,
                    intf.getName() + "   " + getMACAddress(intf.getName()));

            List<InetAddress> addrs = Collections.list(intf
                    .getInetAddresses());

            for (InetAddress addr : addrs) {
                // Log.v(TAG, "inside");

                if (!addr.isLoopbackAddress()) {
                    // Log.v(TAG, "isnt loopback");
                    String sAddr = addr.getHostAddress().toUpperCase();
                    Log.v(TAG, "ip=" + sAddr);

                    boolean isIPv4 = InetAddressUtils.isIPv4Address(sAddr);

                    if (isIPv4) {
                        if (sAddr.contains("192.168.49.")) {
                            Log.v(TAG, "ip = " + sAddr);
                            return sAddr;
                        }
                    }

                }

            }
        }

    } catch (Exception ex) {
        Log.v(TAG, "error in parsing");
    } // for now eat exceptions
    Log.v(TAG, "returning empty ip address");
    return "";
}

public static String getMACAddress(String interfaceName) {
        try {
            List<NetworkInterface> interfaces = Collections
                    .list(NetworkInterface.getNetworkInterfaces());

            for (NetworkInterface intf : interfaces) {
                if (interfaceName != null) {
                    if (!intf.getName().equalsIgnoreCase(interfaceName))
                        continue;
                }
                byte[] mac = intf.getHardwareAddress();
                if (mac == null)
                    return "";
                StringBuilder buf = new StringBuilder();
                for (int idx = 0; idx < mac.length; idx++)
                    buf.append(String.format("%02X:", mac[idx]));
                if (buf.length() > 0)
                    buf.deleteCharAt(buf.length() - 1);
                return buf.toString();
            }
        } catch (Exception ex) {
        } // for now eat exceptions
        return "";
        /*
         * try { // this is so Linux hack return
         * loadFileAsString("/sys/class/net/" +interfaceName +
         * "/address").toUpperCase().trim(); } catch (IOException ex) { return
         * null; }
         */
    }

Answer 3

Just as reference: I'm the developer of the WiFi-Shoot (a direct file transfer app via WiFi Direct).

Unfortunately, there's no way to get your own IP address, and the general principle of operation is slightly different:

• All the operations will be made with the WiFiP2PManager
• call initialize to get a Channel, all other operations needs this channel.
• after you discoverPeers and connect to one of them
• you can requestGroupInfo that will tell you if that device is the group owner and what is the group owner IP address. So non-owners can connect to the owner using the supplied address and the owner will listen to connections.
• you can also requestPeers that will give you a list of all connected peers. That includes MAC addresses and names.

The call Context.getSystemService(Context.WIFI_P2P_SERVICE) will give you a WiFiP2PManager.

And yes, you'll need a bunch of WiFI permission such as ACCESS_WIFI_STATE, CHANGE_WIFI_STATE among others.