Get IP address, mac address of all interface

C/C++ Way

Here is a short example of how to get the ip address, mac address of all network interface in linux from a c++ program.
This code is available for all Linux distributions even though I tested on the Ubuntu 18.04.

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <unistd.h>
#include <string.h>
#include <string>
#include <sys/types.h>
#include <ifaddrs.h>
#include <linux/if_packet.h>
#include <net/ethernet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <sys/ioctl.h>

using namespace std;


unsigned char * getMACAddress(const char *pinterface)
{
    static unsigned char mac[8];
    int sock = socket(PF_INET, SOCK_DGRAM, 0);
    struct ifreq req;
    int i = 0;
    memset(&req, 0, sizeof(req));
    strncpy(req.ifr_name, pinterface, IF_NAMESIZE - 1);
    if (ioctl(sock, SIOCGIFHWADDR, &req) < 0) {
        perror("ioctl");
        exit(EXIT_FAILURE);
    }
    memcpy(&mac, req.ifr_hwaddr.sa_data, 6);
    mac[6] = 0x00;
/*
    for(i=0;i<6;i++) {
        printf("%.2X", (unsigned char) req.ifr_hwaddr.sa_data[i]);
        if (i < 5) printf(":");
    }
    printf("\n");
*/
    close(sock);
    return mac;
}


const char *printMac(unsigned char *mac){
    static char address[32];

    sprintf(address, "%.2X:%.2X:%.2X:%.2X:%.2X:%.2X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    return address;

}
string getIPAddress(){
    string ipAddress="Unable to get IP Address";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    unsigned char mac[8];
    int i;
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_addr = interfaces;
        while(temp_addr != NULL) {
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                memcpy(mac ,getMACAddress(temp_addr->ifa_name) , 6);
                ipAddress=inet_ntoa(((struct sockaddr_in*)temp_addr->ifa_addr)->sin_addr);
                cout << "interface name:" << temp_addr->ifa_name << "  MAC:" << printMac(mac)<< "  IP Address:" << ipAddress.c_str() <<endl;
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    // Free memory
    freeifaddrs(interfaces);
    return ipAddress;
}



int main(int argc, char *argv[])
{
        getIPAddress();
        return 0;

}

You don't need to link any library. Hust compile the code.

g++ main.cpp

Now run the code. You can get the mac address, ip address of all the interfaces.

root@spypiggy-ubuntu:/usr/local/src# ./a.out
interface name:lo  MAC:00:00:00:00:00:00  IP Address:127.0.0.1
interface name:enp4s0  MAC:E0:D5:5E:E6:1A:3E  IP Address:192.168.0.220

Python Way

Several methods are possible, but the psutil module is the most convenient.

First, install psutil. To install psutil, you must have python-dev and build-essentials installed.

[root@tone-ivr2 dialplan]#apt-get install python3-dev build-essentials
[root@tone-ivr2 dialplan]#pip3 install psutil

If you use psutil, you can get interface information and IP address by using the following simple code.

import psutil
import socket


def get_interface_info():
    results = []
    for interface in sorted(psutil.net_if_addrs().keys()):
        ip_address = ""
        mac_address = ""
        for addr in psutil.net_if_addrs()[interface]:
            if addr.family == socket.AF_INET:
                ip_address = addr.address
            if addr.family == psutil.AF_LINK:
                mac_address = addr.address
        results.append({"id": interface, "name": interface, "ip_address": ip_address,"mac_address": mac_address})
    return results


results = get_interface_info()

for result in results:
    print('===============================')
    print('ID:%s'%result["id"])
    print('NAME:%s'%result["name"])
    print('IP:%s'%result["ip_address"])
    print('MAC:%s'%result["mac_address"])

print('===============================')

If you run the code you will see that it gets the IP and MAC information for all interfaces.

[root@tone-ivr2 mac]# python3 mac.py
interface[eno1]  MAC Address : ac:1f:6b:f6:28:3a
interface[eno2]  MAC Address : ac:1f:6b:f6:28:3b
interface[lo]  MAC Address : 00:00:00:00:00:00
===============================
ID:eno1
NAME:eno1
IP:221.139.49.54
MAC:ac:1f:6b:f6:28:6a
===============================
ID:eno2
NAME:eno2
IP:
MAC:ac:1f:6b:f6:28:6b
===============================
ID:lo
NAME:lo
IP:127.0.0.1
MAC:00:00:00:00:00:00
===============================