net.cc

#ifndef NET_H
#define NET_H

#define _GNU_SOURCE     /* To get defns of NI_MAXSERV and NI_MAXHOST */
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netdb.h>
#include <ifaddrs.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/if_link.h>
#include <vector>
#include <string>
#include <iostream>

using namespace std ;

class NET {
    public:
    
    struct ifaddrs *ifaddr;
    int family, s;
    char host[NI_MAXHOST];
    
    vector <string> addresses ;
    
    NET () {
        if (getifaddrs(&ifaddr) == -1) {
           perror("getifaddrs");
           exit(EXIT_FAILURE);
        }

        /* Walk through linked list, maintaining head pointer so we
          can free list later. */

        for (struct ifaddrs *ifa = ifaddr; ifa != NULL;
                ifa = ifa->ifa_next) {
           if (ifa->ifa_addr == NULL)
               continue;

           family = ifa->ifa_addr->sa_family;

           /* Display interface name and family (including symbolic
              form of the latter for the common families). */

           printf("%-8s %s (%d)\n",
                  ifa->ifa_name,
                  (family == AF_PACKET) ? "AF_PACKET" :
                  (family == AF_INET) ? "AF_INET" :
                  (family == AF_INET6) ? "AF_INET6" : "???",
                  family);

           /* For an AF_INET* interface address, display the address. */

           if (family == AF_INET || family == AF_INET6) {
               s = getnameinfo(ifa->ifa_addr,
                       (family == AF_INET) ? sizeof(struct sockaddr_in) :
                                             sizeof(struct sockaddr_in6),
                       host, NI_MAXHOST,
                       NULL, 0, NI_NUMERICHOST);
               if (s != 0) {
                   printf("getnameinfo() failed: %s\n", gai_strerror(s));
                   exit(EXIT_FAILURE);
               }

               printf("\t\taddress: <%s>\n", host);
               if (family == AF_INET)
                    addresses.push_back (string (host));

           } else if (family == AF_PACKET && ifa->ifa_data != NULL) {
               struct rtnl_link_stats *stats = (struct rtnl_link_stats *) ifa->ifa_data;

               printf("\t\ttx_packets = %10u; rx_packets = %10u\n"
                      "\t\ttx_bytes   = %10u; rx_bytes   = %10u\n",
                      stats->tx_packets, stats->rx_packets,
                      stats->tx_bytes, stats->rx_bytes);
           }
        }

        freeifaddrs(ifaddr);
        //~ exit(EXIT_SUCCESS);
    }
} ;

#ifdef TEST
int main (int argc, char ** argv) {
    NET n = NET ();
    clog << "Got the following addresses" << endl;
    for (int i= 0 ; i < n.addresses.size () ; i ++) {
        clog << n.addresses.at (i).c_str ()  << endl;
    }
}
#endif

#endif