linux下,ioctl检测网卡物理连接

/* Check network adapter is up or down */
// Note: one or two adapter drivers may be not support this method
// exemple: based virtual machine

#include
#include
#include
#include
#include
#include
#include
#include

const char* VERSION = "0.6.0.48 --maintain by isnowran";

struct mii_data
{
__u16 phy_id;
__u16 reg_num;
__u16 val_in;
__u16 val_out;
};

int main( int argc, char* argv[] )
{
if( argc != 2 )
{
printf( "Version: %s\n", VERSION );
printf( "Useage: argv[0] ethNO.\n" );
return 0;
}

int skfd = 0;
if( ( skfd = socket( AF_INET, SOCK_DGRAM, 0 ) ) < 0 )
{
perror( "socket" );
return -1;
}

struct ifreq ifr;
bzero( &ifr, sizeof( ifr ) );
strncpy( ifr.ifr_name, argv[1], IFNAMSIZ - 1 );
ifr.ifr_name[IFNAMSIZ - 1] = 0;
if( ioctl( skfd, SIOCGMIIPHY, &ifr ) < 0 )
{
perror( "ioctl" );
return -1;
}

struct mii_data* mii = NULL;
mii = (struct mii_data*)&ifr.ifr_data;
mii->reg_num = 0x01;
if( ioctl( skfd, SIOCGMIIREG, &ifr ) < 0 )
{
perror( "ioctl2" );
return -1;
}

if( mii->val_out & 0x0004 )
printf( "Linkup\n" );
else
printf( "Linkdown\n" );

close( skfd );
return 0;
}