The MAC (Media Access Control) address is an identifier that is associated with a network adapter and uniquely identifies a device on a network. A MAC address consists of 12 hexadecimal numbers, typically formatted as follows

XX:XX:XX:YY:YY:YY

The XX values in a MAC address identify the manufacturer, the YY values are the serial number assigned to the network adapter.

The MAC address can be useful if you need a way to uniquely identify a device – this can be used as a substitute for the UDID value that is now deprecated in iOS 5 and greater.

The code below shows how to get the MAC address on an iOS device:

  1. #include <sys/socket.h>
  2. #include <sys/sysctl.h>
  3. #include <net/if.h>
  4. #include <net/if_dl.h>
  5.  
  6. - (NSString *)getMacAddress
  7. {
  8. int mgmtInfoBase[6];
  9. char *msgBuffer = NULL;
  10. NSString *errorFlag = NULL;
  11. size_t length;
  12.  
  13. // Setup the management Information Base (mib)
  14. mgmtInfoBase[0] = CTL_NET; // Request network subsystem
  15. mgmtInfoBase[1] = AF_ROUTE; // Routing table info
  16. mgmtInfoBase[2] = 0;
  17. mgmtInfoBase[3] = AF_LINK; // Request link layer information
  18. mgmtInfoBase[4] = NET_RT_IFLIST; // Request all configured interfaces
  19.  
  20. // With all configured interfaces requested, get handle index
  21. if ((mgmtInfoBase[5] = if_nametoindex("en0")) == 0)
  22. errorFlag = @"if_nametoindex failure";
  23. // Get the size of the data available (store in len)
  24. else if (sysctl(mgmtInfoBase, 6, NULL, &length, NULL, 0) < 0)
  25. errorFlag = @"sysctl mgmtInfoBase failure";
  26. // Alloc memory based on above call
  27. else if ((msgBuffer = malloc(length)) == NULL)
  28. errorFlag = @"buffer allocation failure";
  29. // Get system information, store in buffer
  30. else if (sysctl(mgmtInfoBase, 6, msgBuffer, &length, NULL, 0) < 0)
  31. {
  32. free(msgBuffer);
  33. errorFlag = @"sysctl msgBuffer failure";
  34. }
  35. else
  36. {
  37. // Map msgbuffer to interface message structure
  38. struct if_msghdr *interfaceMsgStruct = (struct if_msghdr *) msgBuffer;
  39.  
  40. // Map to link-level socket structure
  41. struct sockaddr_dl *socketStruct = (struct sockaddr_dl *) (interfaceMsgStruct + 1);
  42.  
  43. // Copy link layer address data in socket structure to an array
  44. unsigned char macAddress[6];
  45. memcpy(&macAddress, socketStruct->sdl_data + socketStruct->sdl_nlen, 6);
  46.  
  47. // Read from char array into a string object, into traditional Mac address format
  48. NSString *macAddressString = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X",
  49. macAddress[0], macAddress[1], macAddress[2], macAddress[3], macAddress[4], macAddress[5]];
  50. NSLog(@"Mac Address: %@", macAddressString);
  51.  
  52. // Release the buffer memory
  53. free(msgBuffer);
  54.  
  55. return macAddressString;
  56. }
  57.  
  58. // Error...
  59. NSLog(@"Error: %@", errorFlag);
  60.  
  61. return errorFlag;
  62. }
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>

- (NSString *)getMacAddress
{
int mgmtInfoBase[6];
char *msgBuffer = NULL;
NSString *errorFlag = NULL;
size_t length;

// 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";
// Get the size of the data available (store in len)
else if (sysctl(mgmtInfoBase, 6, NULL, &length, NULL, 0) < 0)
errorFlag = @"sysctl mgmtInfoBase failure";
// Alloc memory based on above call
else if ((msgBuffer = malloc(length)) == NULL)
errorFlag = @"buffer allocation failure";
// Get system information, store in buffer
else if (sysctl(mgmtInfoBase, 6, msgBuffer, &length, NULL, 0) < 0)
{
free(msgBuffer);
errorFlag = @"sysctl msgBuffer failure";
}
else
{
// Map msgbuffer to interface message structure
struct if_msghdr *interfaceMsgStruct = (struct if_msghdr *) msgBuffer;

// Map to link-level socket structure
struct sockaddr_dl *socketStruct = (struct sockaddr_dl *) (interfaceMsgStruct + 1);

// Copy link layer address data in socket structure to an array
unsigned char macAddress[6];
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;
}

// Error...
NSLog(@"Error: %@", errorFlag);

return errorFlag;
}

The output will look as follows: Mac Address: E0:F8:47:C0:E3:C9

 

UPD: Update code to fixed version. Thx to C?ur