今天在CocoaChina上看到有人发帖在询问如何在Mac OSX下获得网卡的物理地址，恰好最近在学习IOKit的一些知识，所以通过IOKit的接口肯定是可以很方便的拿到MAC地址信息的，但不知道还有没有其它更方便的API了，所以我姑且贴出一段通过IOKit去获得网卡MAC地址的代码：

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    kern_return_t kr;
    CFMutableDictionaryRef matchDict;
    io_iterator_t iterator;
    io_registry_entry_t entry;
    
    matchDict = IOServiceMatching("IOEthernetInterface");
    kr = IOServiceGetMatchingServices(kIOMasterPortDefault, matchDict, &iterator);
    
    NSDictionary *resultInfo = nil;
    
    while ((entry = IOIteratorNext(iterator)) != 0)
    {
        CFMutableDictionaryRef properties=NULL;
        kr = IORegistryEntryCreateCFProperties(entry,
                                               &properties,
                                               kCFAllocatorDefault,
                                               kNilOptions);
        if (properties)
        {
            resultInfo = (__bridge_transfer NSDictionary *)properties;
            NSString *bsdName = [resultInfo objectForKey:@"BSD Name"];
            NSData *macData = [resultInfo objectForKey:@"IOMACAddress"];
            if (!macData)
            {
                continue;
            }
            
            NSMutableString *macAddress = [[NSMutableString alloc] init];
            const UInt8 *bytes = [macData bytes];
            for (int i=0; i<macData.length; i++)
            {
                [macAddress appendFormat:@"%02x",*(bytes+i)];
            }
            
            //打印Mac地址
            if (bsdName && macAddress)
            {
                NSLog(@"网卡:%@\nMac地址:%@\n",bsdName,macAddress);
            }
        }
    }
    
    IOObjectRelease(iterator);
}

同时可以通过iOS 获取网卡地址的方式获取网卡地址

+ (NSString *)currentMACAddress {
    char addr[64];
    int                 mib[6];
    size_t              len;
    char                buf[1024];
    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 FALSE;
    }
    
    if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 1/n");
        return FALSE;
    }
    
    if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 2");
        return FALSE;
    }
    
    ifm = (struct if_msghdr *)buf;
    sdl = (struct sockaddr_dl *)(ifm + 1);
    ptr = (unsigned char *)LLADDR(sdl);
    
    sprintf(addr, "%.2X:%.2X:%.2X:%.2X:%.2X:%.2X", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5));
    NSString *macAddress = [[NSString alloc] initWithCString:addr encoding:NSASCIIStringEncoding];
    return macAddress;
}