linux组播绑定网卡,Linux---指定网卡发送UDP组播

#include #define UDP_ADDR "239.255.255.250"

#define UDP_PORT 3702

#define SEND_PORT 3702

#define MAC_SIZE 18

#define IP_SIZE 16

#define ETHX "eth0"

// function declare

int get_local_mac(const char *eth_inf, char *mac); // 获取本机mac

int get_local_ip(const char *eth_inf, char *ip); // 获取本机ip

// 获取本机mac

int get_local_mac(const char *eth_inf, char *mac)

{

struct ifreq ifr;

int sd;

bzero(&ifr, sizeof(struct ifreq));

if( (sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)

{

printf("get %s mac address socket creat error\n", eth_inf);

return -1;

}

strncpy(ifr.ifr_name, eth_inf, sizeof(ifr.ifr_name) - 1);

if(ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)

{

printf("get %s mac address error\n", eth_inf);

close(sd);

return -1;

}

snprintf(mac, MAC_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x",

(unsigned char)ifr.ifr_hwaddr.sa_data[0],

(unsigned char)ifr.ifr_hwaddr.sa_data[1],

(unsigned char)ifr.ifr_hwaddr.sa_data[2],

(unsigned char)ifr.ifr_hwaddr.sa_data[3],

(unsigned char)ifr.ifr_hwaddr.sa_data[4],

(unsigned char)ifr.ifr_hwaddr.sa_data[5]);

close(sd);

return 0;

}

//获取网卡对应IP地址[其中eth是网卡名字 如“eth0” “eth1”等,ipaddr是输出参数]

// 获取本机ip

int get_local_ip(const char *eth_inf, char *ip)

{