Android NDK get mobile network info - android

I have C++ code which can take a network info(struct ifaddrs) via netlink.
But I can't obtain next field:
network type - WIFI or MOBILE
mobile network type - like NETWORK_TYPE_CDMA, NETWORK_TYPE_LTE etc..
Any idea how can I get this info without Java(only C/C++) ?
How can I get info about mobile internet connection and assign it with network?

Related

how to get cellular connection data

I can not find any plugin to get android cellular data (I want to know first if My connection is of type 2G, 3G or 4G then at least I want to get my signal strength and some other info but those 2 are very important).
Yes there is plugin available for check internet connection state in different parameter.like downloading and uploading data speed.
internet_speed_test
Like this,
Var unitText = unit == SpeedUnit.Kbps;

How to get android device connected data network adapter name, ip and type of network?

Requirement is:
Need following parameters from android device connected network
1) network ip
2) network type
3) network adapter name
Could you please suggest me to get above params in Java or C.

How many devices can i connect with Wi-Fi P2P?

I need to connect 20+ android devices in a client-server network. Each client Android device will be communicating with the server Android device and vice versa. The client devices do not need to communicate with each other.
The server device would need access to internet for a brief period while connected to the clients.
My question is, can Wi-Fi P2P support that many connections reliably? And if yes, how do I go about implementing them?
Or will I have to ensure that all devices are on the same WLAN?
From experience, in a real-world deployment of an Android Wi-Fi Direct application, 20 devices should not be an issue.
Theoretically, the maximum number of devices in a Wi-Fi P2P group, where the GO is an Android device, is 254. The group owner is assigned the IP, 192.168.49.1. Clients are assigned an IP from the range, 192.168.49.2 to 192.168.49.254.
The group owner address is defined by the following in WifiP2pServiceImpl.java:
/* Is chosen as a unique address to avoid conflict with
the ranges defined in Tethering.java */
private static final String SERVER_ADDRESS = "192.168.49.1";
Determining the range for the clients is done as follows:
In WifiP2pServiceImpl.java, the startDhcpServer(String intf) method will start the DHCP server for a given interface - not a surprise. This method is called when the group has started and the device is the group owner.
Taking a closer look at this code, we can see that on the InterfaceConfiguration object, the link address is set to 192.168.49.1 and the prefix length is 24 (prefix length is the number of bits set in a subnet mask, here equivalent to 255.255.255.0) - this implies the answer, but we can dig a little further.
ifcg = mNwService.getInterfaceConfig(intf);
ifcg.setLinkAddress(new LinkAddress(NetworkUtils.numericToInetAddress(
SERVER_ADDRESS), 24));
ifcg.setInterfaceUp();
mNwService.setInterfaceConfig(intf, ifcg);
Next, the following commands will restart tethering with the DHCP range specified by the String[], tetheringDhcpRanges. The calls of mNwService (Network Management Service) methods will execute the appropriate netd commands.
ConnectivityManager cm = (ConnectivityManager) mContext.getSystemService(
Context.CONNECTIVITY_SERVICE);
String[] tetheringDhcpRanges = cm.getTetheredDhcpRanges();
if (mNwService.isTetheringStarted()) {
if (DBG) logd("Stop existing tethering and restart it");
mNwService.stopTethering();
}
mNwService.tetherInterface(intf);
mNwService.startTethering(tetheringDhcpRanges);
And cm.getTetheredDhcpRanges() is ultimately a reference to the following (ConnectivityManager.getTetheredDhcpRanges() -> ConnectivityService.getTetheredDhcpRanges() -> Tethering.getTetheredDhcpRanges()):
// USB is 192.168.42.1 and 255.255.255.0
// Wifi is 192.168.43.1 and 255.255.255.0
// BT is limited to max default of 5 connections. 192.168.44.1 to 192.168.48.1
// with 255.255.255.0
// P2P is 192.168.49.1 and 255.255.255.0
private String[] mDhcpRange;
private static final String[] DHCP_DEFAULT_RANGE = {
"192.168.42.2", "192.168.42.254", "192.168.43.2", "192.168.43.254",
"192.168.44.2", "192.168.44.254", "192.168.45.2", "192.168.45.254",
"192.168.46.2", "192.168.46.254", "192.168.47.2", "192.168.47.254",
"192.168.48.2", "192.168.48.254", "192.168.49.2", "192.168.49.254",
}
and:
mDhcpRange = context.getResources().getStringArray(
com.android.internal.R.array.config_tether_dhcp_range);
if ((mDhcpRange.length == 0) || (mDhcpRange.length % 2 ==1)) {
mDhcpRange = DHCP_DEFAULT_RANGE;
}
in com.android.server.connectivity.Tethering.
Of course, it is possible for the device manufacturer to change this code, so this is also worth considering.
For those planning to deploy applications where there will be many users, a mechanism to allow a more than one device to be GO is required. If data needs to be synchronised between devices, it is simple to simulate "churn" and have GOs only be a GO for a time period before becoming a client to another GO and synchronising any data.
The max number as far as I know is not specified, so you would need to test that out to be certain. Also there could be differences between hardware.
Anyway, the basic implementation would be rather simple. The server would call GreateGroup, so it would be the Groupowner in all cases. And then start locals service advertising. Clients then would simply look for the advertisement and once they see it, they would start connection process to the server. One the server connection is made over Wifi direct you would simply start socket communications from the client to the server (server would have listening socket on all times).
Note that connection would require user to click on the dialog showed when client tries to connect to the group owner. And if you want to get rid of this. Then you could actually use the Accesspoint created by GreateGroup, and add the access point name as well as the password to the advertising. Then your clients could actually use the accesspoint to connect (like to any Wlan accesspoint)
Note though that the Wifi Direct way, would not interfere with Wifi connections, not would it require it. But the accesspoint way would mean that any existing Wifi connection from the client would be disconnected, and the device thinks that the connection made to the server would provide normal internet connectivity.
Remember that devices don't need to be connected to a network to connect to each other. Wi-Fi Direct allows them to connect directly.
Here is a list of Wi-Fi Direct resources that you may find useful: https://groups.google.com/forum/#!topic/wi-fi-direct/uWpuOzHY6y0
I'd recommend following Android's Service Discovery Demo and try implementing it yourself. And here is the source code for the demo.

Conditioned Data Connection

How can I programmatically check that internet access in a android device is only over Wi-Fi and not over Packet Data connections like UMTS EDGE or GPRS ?
if you want your app to only use one particular type of data connection, you can form if/else logic and use check for mobile-network-access and wifi-access and give command accordingly
you can refer to mobile-network-access and wifi-access questions of stackoverflow for check on connection availability

Get MAC Address of android device without Wifi

How do I get the MAC-Address of the network interface of an android device which doesn't have a Wifi-Interface (e.g. the android emulator)? WifiInfo obtained via the WifiManager returns null.
EDIT
To be more clear: I have to communicate with an existing network protocol (not designed by me) on the local network where I have to send the mac address of the communicating interface within the payload during a registration phase.
I'm going to take a leap and assume that you want this MAC address in order to establish a unique identifier for the device. Mac Addresses are not the way to do this.
There's an Android Developer Blog post titled "Identifying App Installations" which covers the topic of generating unique ID's fairly well, including the popular methods, and the pros/cons. It's definitely worth a read. Quite relevant to this post is the following quote:
It may be possible to retrieve a Mac address from a device’s WiFi or Bluetooth hardware. We do not recommend using this as a unique identifier. To start with, not all devices have WiFi. Also, if the WiFi is not turned on, the hardware may not report the Mac address.
The options available to you instead include TelephonyManager.getDeviceId(), android.os.Build.SERIAL, and Settings.Secure.ANDROID_ID, all of which are covered in more detail in the linked post.
Read /sys/class/net/[something]/address as a text file
But it's unlikely to be useful in the way you think.
See this post where I have submitted Utils.java example to provide pure-java implementations.
Utils.getMACAddress("wlan0");
Utils.getMACAddress("eth0");
Utils.getIPAddress(true); // IPv4
Utils.getIPAddress(false); // IPv6
What is the network interface you want the MAC address of? If there's no wifi, you certainly can't get the wifi device's MAC address. It represents the physical hardware and if that's not present, it simply doesn't exist.
To get wifi MAC of android device using adb:
adb shell getprop ril.wifi_macaddr
Use the following code in Java to get it programmatically:
Process p = Runtime.getRuntime.exec("adb", "shell", "getprop", "ril.wifi_macaddr")
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream());
String macAddress = br.readLine();

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