Linux- 如何由User Space透過ioctl得知MAC Address

可以直接寫個程式碼透過 SIOCGIFHWADDR 這個關鍵字,
使用方法 ioctl( SIOCGIFHWADDR );
去Kernel Space得到資訊再傳回User Space

範例如下:

#include <stdio.h>#include <string.h>#include <unistd.h>#include <net/if.h>#include <sys/ioctl.h>#include <sys/types.h>#include <sys/socket.h>int GetMac( const char *ifname, unsigned char *mac ){	int	sock, ret;	struct	ifreq	ifr;	sock = socket( AF_INET, SOCK_STREAM, 0 );	if ( sock < 0 ) {		perror( "socket" );		return -1;	}	memset( &ifr, 0, sizeof(ifr) );	strcpy( ifr.ifr_name, ifname );	ret = ioctl( sock, SIOCGIFHWADDR, &ifr, sizeof(ifr) );	if ( ret == 0 ) {		memcpy( mac, ifr.ifr_hwaddr.sa_data, 6 );	} else {		perror( "ioctl" );	}	close( sock );	return ret;}int main( int argc, char **argv ){	int	ret;	char	ifname[IFNAMSIZ];	unsigned char	mac[6];	if ( argc == 1 ) {		strcpy( ifname, "eth0" );	} else {		strcpy( ifname, argv[1] );	}	memset( mac, 0, sizeof(mac) );	ret = GetMac( ifname, mac );	if ( ret == 0 ) {		printf( "%s mac address is: [%02X:%02X:%02X:%02X:%02X:%02X]\n", ifname, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5] );	} else {		fprintf( stderr, "Can't get %s's mac address\n", ifname );	}	return 0;}