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cinterfaceipmac-address

MAC address with getifaddrs


Is there a way to get interface's MAC address via getifaddrs() ?

I already have this, to get IP addresses, but I have kinda missed MAC. Ive tried to look for the information in getifaddrs(), but there is nothing about MAC addresses

struct ifaddrs *iflist, *iface;

  if (getifaddrs(&iflist) < 0) 
  {
      perror("getifaddrs");
  }

  char addrp[INET6_ADDRSTRLEN];
  char macp[INET6_ADDRSTRLEN];
  int i=0;

  for (iface = iflist; iface; iface = iface->ifa_next) 
  {
    int af = iface->ifa_addr->sa_family;
    const void *addr;
    const void *mac;

      switch (af) 
      {
        case AF_INET:
          addr = &((struct sockaddr_in *)iface->ifa_addr)->sin_addr;
          break;
      //get mac address somehow?
        default:
          addr = NULL;
      }

      if (addr) 
      {
        if (inet_ntop(af, addr, addrp, sizeof addrp) == NULL)
        {
           perror("inet_ntop");
           continue;
        }
    if (inet_ntop(af, mac, macp, sizeof macp) == NULL) // this is already for MAC add
        {
           perror("inet_ntop");
           continue;
        }
    if (strcmp(addrp, "127.0.0.1") != 0) 
    {
       strcat(tableO[i].IPaddr, addrp);
       strcat(tableO[i].MACaddr, macp);
       i++;
    }
      }

Thanks


Solution

  • Here is the code for getting IP and MAC addresses

    #include <stdio.h>
    #include <string.h>
    #include <sys/socket.h>
    #include <arpa/inet.h>
    #include <netdb.h>
    #include <sys/ioctl.h>
    #include <net/if.h>
    
    int main(void)
    {
      char buf[8192] = {0};
      struct ifconf ifc = {0};
      struct ifreq *ifr = NULL;
      int sck = 0;
      int nInterfaces = 0;
      int i = 0;
      char ip[INET6_ADDRSTRLEN] = {0};
      char macp[19];
      struct ifreq *item;
      struct sockaddr *addr;
    
      /* Get a socket handle. */
      sck = socket(PF_INET, SOCK_DGRAM, 0);
      if(sck < 0) 
      {
        perror("socket");
        return 1;
      }
    
      /* Query available interfaces. */
      ifc.ifc_len = sizeof(buf);
      ifc.ifc_buf = buf;
      if(ioctl(sck, SIOCGIFCONF, &ifc) < 0) 
      {
        perror("ioctl(SIOCGIFCONF)");
        return 1;
      }
    
      /* Iterate through the list of interfaces. */
      ifr = ifc.ifc_req;
      nInterfaces = ifc.ifc_len / sizeof(struct ifreq);
    
      for(i = 0; i < nInterfaces; i++) 
      {
        item = &ifr[i];
    
        addr = &(item->ifr_addr);
    
        /* Get the IP address*/
        if(ioctl(sck, SIOCGIFADDR, item) < 0) 
        {
          perror("ioctl(OSIOCGIFADDR)");
        }
    
        if (inet_ntop(AF_INET, &(((struct sockaddr_in *)addr)->sin_addr), ip, sizeof ip) == NULL) //vracia adresu interf
            {
               perror("inet_ntop");
               continue;
            }
    
        /* Get the MAC address */
        if(ioctl(sck, SIOCGIFHWADDR, item) < 0) {
          perror("ioctl(SIOCGIFHWADDR)");
          return 1;
        }
    
        /* display result */
    
        sprintf(macp, " %02x:%02x:%02x:%02x:%02x:%02x", 
        (unsigned char)item->ifr_hwaddr.sa_data[0],
        (unsigned char)item->ifr_hwaddr.sa_data[1],
        (unsigned char)item->ifr_hwaddr.sa_data[2],
        (unsigned char)item->ifr_hwaddr.sa_data[3],
        (unsigned char)item->ifr_hwaddr.sa_data[4],
        (unsigned char)item->ifr_hwaddr.sa_data[5]);
    
        printf("%s %s ", ip, macp);
    
      }
    
      return 0;
    }