MACアドレスを取得する(Windows/Linux/BSD(OSX))

getmacaddress.c

# include <stdio.h>

# if defined(WIN32) || (!defined(__GNUC__) && !defined(__clang__))
	#include <winsock2.h>
	#include <iphlpapi.h>
	#include <stdlib.h>
	#pragma comment(lib, "IPHLPAPI.lib")
# elif defined(__linux__)
	#include <string.h> //strncpy
	#include <sys/ioctl.h>
	#include <sys/socket.h>
	#include <net/if.h>
# else
	//bsd
	#include <sys/types.h> //FreeBSD u_int
	#include <ifaddrs.h>
	#include <net/if.h>
	#include <net/if_dl.h>
	#include <net/if_types.h>
# endif

void getmacaddress(char *mac_address){
# if defined(WIN32) || (!defined(__GNUC__) && !defined(__clang__))
	//MSDNのサンプルコード
	PIP_ADAPTER_INFO pAdapterInfo;
	PIP_ADAPTER_INFO pAdapter;
	ULONG ulOutBufLen = sizeof(IP_ADAPTER_INFO);
	unsigned char *addr;

	mac_address[0]=0;
	pAdapterInfo = (IP_ADAPTER_INFO*)malloc(sizeof(IP_ADAPTER_INFO));
	if(!pAdapterInfo)return;
	if(GetAdaptersInfo(pAdapterInfo, &ulOutBufLen) == ERROR_BUFFER_OVERFLOW){
		free(pAdapterInfo);
		pAdapterInfo = (IP_ADAPTER_INFO*)malloc(ulOutBufLen);
		if(!pAdapterInfo)return;
	}

	if(GetAdaptersInfo(pAdapterInfo, &ulOutBufLen) == NO_ERROR){
		pAdapter = pAdapterInfo;
		if(pAdapter){
			addr = pAdapter->Address;
			sprintf(mac_address,"%02x:%02x:%02x:%02x:%02x:%02x",
				addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
		}
	}
	free(pAdapterInfo);
# elif defined(__linux__)
	//http://field-notes.hatenablog.jp/entry/20101216/1292467817
	mac_address[0]=0;
	struct ifreq *ifr, *ifend;
	struct ifreq ifreq;
	struct ifconf ifc;
	struct ifreq ifs[16];
	int fd;
	unsigned char *addr;

	fd = socket(AF_INET, SOCK_DGRAM, 0);
	ifc.ifc_len = sizeof(ifs);
	ifc.ifc_req = ifs;
	if(ioctl(fd, SIOCGIFCONF, &ifc)<0){close(fd);return;}

	ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
	for(ifr = ifc.ifc_req;ifr < ifend;ifr++){
		if(ifr->ifr_addr.sa_family == AF_INET){
			strncpy(ifreq.ifr_name, ifr->ifr_name, sizeof(ifreq.ifr_name));
			if(ioctl(fd, SIOCGIFHWADDR, &ifreq)<0)continue;
			addr = ifreq.ifr_hwaddr.sa_data;
			sprintf(mac_address,"%02x:%02x:%02x:%02x:%02x:%02x",
					addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
		}
	}
	close(fd);
# else
	//bsd
	mac_address[0]=0;
	struct ifaddrs *ifa_list, *ifa; 
	struct sockaddr_dl *dl; 
	unsigned char *addr;
	if(getifaddrs(&ifa_list)<0)return;
	for(ifa = ifa_list;ifa;ifa = ifa->ifa_next){ 
		dl = (struct sockaddr_dl*)ifa->ifa_addr; 
		if (dl->sdl_family == AF_LINK && dl->sdl_type == IFT_ETHER) {
			addr = (unsigned char*)LLADDR(dl);
			sprintf(mac_address,"%02x:%02x:%02x:%02x:%02x:%02x",
				addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
			return;
		}
	} 
	freeifaddrs(ifa_list); 
# endif
}