#include <sys/sysctl.h> #include <net/if.h> #include <net/if_dl.h> 

// Return the local MAC addy // Courtesy of FreeBSD hackers email list // Accidentally munged during previous update. Fixed thanks to mlamb. - (NSString *) macaddress {      int         mib[6];   size_t       len;   char        *buf;   unsigned char    *ptr;   struct if_msghdr  *ifm;   struct sockaddr_dl *sdl;      mib[0] = CTL_NET;   mib[1] = AF_ROUTE;   mib[2] = 0;   mib[3] = AF_LINK;   mib[4] = NET_RT_IFLIST;      if ((mib[5] = if_nametoindex("en0")) == 0) {     printf("Error: if_nametoindex error/n");     return NULL;   }      if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {     printf("Error: sysctl, take 1/n");     return NULL;   }      if ((buf = malloc(len)) == NULL) {     printf("Could not allocate memory. error!/n");     return NULL;   }      if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {     printf("Error: sysctl, take 2");     return NULL;   }      ifm = (struct if_msghdr *)buf;   sdl = (struct sockaddr_dl *)(ifm + 1);   ptr = (unsigned char *)LLADDR(sdl);   NSString *outstring = [NSString stringWithFormat:@"%02x:%02x:%02x:%02x:%02x:%02x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];    //  NSString *outstring = [NSString stringWithFormat:@"%02x%02x%02x%02x%02x%02x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];      NSLog(@"outString:%@", outstring);      free(buf);      return [outstring uppercaseString]; }

 - (NSString *)getMacAddress {   int         mgmtInfoBase[6];   char        *msgBuffer = NULL;   size_t       length;   unsigned char    macAddress[6];   struct if_msghdr  *interfaceMsgStruct;   struct sockaddr_dl *socketStruct;   NSString      *errorFlag = NULL;      // Setup the management Information Base (mib)   mgmtInfoBase[0] = CTL_NET;    // Request network subsystem   mgmtInfoBase[1] = AF_ROUTE;    // Routing table info   mgmtInfoBase[2] = 0;   mgmtInfoBase[3] = AF_LINK;    // Request link layer information   mgmtInfoBase[4] = NET_RT_IFLIST; // Request all configured interfaces      // With all configured interfaces requested, get handle index   if ((mgmtInfoBase[5] = if_nametoindex("en0")) == 0)     errorFlag = @"if_nametoindex failure";   else   {     // Get the size of the data available (store in len)     if (sysctl(mgmtInfoBase, 6, NULL, &length, NULL, 0) < 0)       errorFlag = @"sysctl mgmtInfoBase failure";     else     {       // Alloc memory based on above call       if ((msgBuffer = malloc(length)) == NULL)         errorFlag = @"buffer allocation failure";       else       {         // Get system information, store in buffer         if (sysctl(mgmtInfoBase, 6, msgBuffer, &length, NULL, 0) < 0)           errorFlag = @"sysctl msgBuffer failure";       }     }   }      // Befor going any further...   if (errorFlag != NULL)   {     NSLog(@"Error: %@", errorFlag);     return errorFlag;   }      // Map msgbuffer to interface message structure   interfaceMsgStruct = (struct if_msghdr *) msgBuffer;      // Map to link-level socket structure   socketStruct = (struct sockaddr_dl *) (interfaceMsgStruct + 1);      // Copy link layer address data in socket structure to an array   memcpy(&macAddress, socketStruct->sdl_data + socketStruct->sdl_nlen, 6);      // Read from char array into a string object, into traditional Mac address format   NSString *macAddressString = [NSString stringWithFormat:@"%02x:%02x:%02x:%02x:%02x:%02x",                  macAddress[0], macAddress[1], macAddress[2],                  macAddress[3], macAddress[4], macAddress[5]];   NSLog(@"Mac Address: %@", macAddressString);      // Release the buffer memory   free(msgBuffer);      return macAddressString; }