Linux – How to tie a network connection to a PID without using lsof or netstat

linuxnetworkingpidsolaris

Is there a way to tie a network connection to a PID (process ID) without forking to lsof or netstat?

Currently lsof is being used to poll what connections belong which process ID. However lsof or netstat can be quite expensive on a busy host and would like to avoid having to fork to these tools.

Is there someplace similar to /proc/$pid where one can look to find this information? I know what the network connections are by examining /proc/net but can't figure out how to tie this back to a pid. Over in /proc/$pid, there doesn't seem to be any network information.

The target hosts are Linux 2.4 and Solaris 8 to 10. If possible, a solution in Perl, but am willing to do C/C++.

additional notes:

I would like to emphasize the goal here is to tie a network connection to a PID. Getting one or the other is trivial, but putting the two together in a low cost manner appears to be difficult. Thanks for the answers to so far!

Best Answer

I don't know how often you need to poll, or what you mean with "expensive", but with the right options both netstat and lsof run a lot faster than in the default configuration.
Examples:

netstat -ltn

shows only listening tcp sockets, and omits the (slow) name resolution that is on by default.

lsof -b -n -i4tcp:80

omits all blocking operations, name resolution, and limits the selection to IPv4 tcp sockets on port 80.

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Android – Detect network connection type on Android

If the problem is to find whether the phone's network is connected and fast enough to meet your demands you have to handle all the network types returned by getSubType().

It took me an hour or two to research and write this class to do just exactly that, and I thought I would share it with others that might find it useful.

Here is a Gist of the class, so you can fork it and edited it.

package com.emil.android.util;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.telephony.TelephonyManager;

/**
 * Check device's network connectivity and speed 
 * @author emil http://stackoverflow.com/users/220710/emil
 *
 */
public class Connectivity {

    /**
     * Get the network info
     * @param context
     * @return
     */
    public static NetworkInfo getNetworkInfo(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        return cm.getActiveNetworkInfo();
    }

    /**
     * Check if there is any connectivity
     * @param context
     * @return
     */
    public static boolean isConnected(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected());
    }

    /**
     * Check if there is any connectivity to a Wifi network
     * @param context
     * @return
     */
    public static boolean isConnectedWifi(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI);
    }

    /**
     * Check if there is any connectivity to a mobile network
     * @param context
     * @return
     */
    public static boolean isConnectedMobile(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE);
    }

    /**
     * Check if there is fast connectivity
     * @param context
     * @return
     */
    public static boolean isConnectedFast(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && Connectivity.isConnectionFast(info.getType(),info.getSubtype()));
    }

    /**
     * Check if the connection is fast
     * @param type
     * @param subType
     * @return
     */
    public static boolean isConnectionFast(int type, int subType){
        if(type==ConnectivityManager.TYPE_WIFI){
            return true;
        }else if(type==ConnectivityManager.TYPE_MOBILE){
            switch(subType){
            case TelephonyManager.NETWORK_TYPE_1xRTT:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_CDMA:
                return false; // ~ 14-64 kbps
            case TelephonyManager.NETWORK_TYPE_EDGE:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
                return true; // ~ 400-1000 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
                return true; // ~ 600-1400 kbps
            case TelephonyManager.NETWORK_TYPE_GPRS:
                return false; // ~ 100 kbps
            case TelephonyManager.NETWORK_TYPE_HSDPA:
                return true; // ~ 2-14 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPA:
                return true; // ~ 700-1700 kbps
            case TelephonyManager.NETWORK_TYPE_HSUPA:
                return true; // ~ 1-23 Mbps
            case TelephonyManager.NETWORK_TYPE_UMTS:
                return true; // ~ 400-7000 kbps
            /*
             * Above API level 7, make sure to set android:targetSdkVersion 
             * to appropriate level to use these
             */
            case TelephonyManager.NETWORK_TYPE_EHRPD: // API level 11 
                return true; // ~ 1-2 Mbps
            case TelephonyManager.NETWORK_TYPE_EVDO_B: // API level 9
                return true; // ~ 5 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPAP: // API level 13
                return true; // ~ 10-20 Mbps
            case TelephonyManager.NETWORK_TYPE_IDEN: // API level 8
                return false; // ~25 kbps 
            case TelephonyManager.NETWORK_TYPE_LTE: // API level 11
                return true; // ~ 10+ Mbps
            // Unknown
            case TelephonyManager.NETWORK_TYPE_UNKNOWN:
            default:
                return false;
            }
        }else{
            return false;
        }
    }

}

Also make sure to add this permission to you AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>

Sources for network speeds include wikipedia & http://3gstore.com/page/78_what_is_evdo_mobile_broadband.html

Best Answer

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