绑定vlan，网卡的demon，如果有多个网卡，多个vlan，网卡的ip设置成一致，那就不能只简单绑定ip来创建socket，
需要绑定网卡设备

客户端udp_client.c

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <linux/sockios.h>
#include <sys/ioctl.h>#include <arpa/inet.h>
#include <errno.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <netinet/in.h>
#include <netpacket/packet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>#define BUF_SIZE    1024
#define INTERFAXENAME "mgbe3_0.14"int sock;int main(int argc, char *argv[])
{int ret = 0;char buf[1024];memset(buf,1,1024);if ( (sock=socket(AF_INET, SOCK_DGRAM, 0)) <0){perror("socket");exit(1);}struct ifreq interface;strncpy(interface.ifr_ifrn.ifrn_name, INTERFAXENAME, sizeof(INTERFAXENAME));if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, (char *)&interface, sizeof(interface))  < 0) // 绑定vlan网卡设备{perror("SO_BINDTODEVICE failed");}struct sockaddr_in addr;memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET;addr.sin_port = htons(31004);addr.sin_addr.s_addr = inet_addr("198.18.36.3");ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));if (ret < 0) {printf("%s: bind 198.18.36.3 failed\n", __FUNCTION__);close(sock);return 0;}elseprintf("bind 198.18.36.3 success \r\n");struct sockaddr_in server_addr;memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(31004);server_addr.sin_addr.s_addr = inet_addr("198.18.36.1");while(1){ret = sendto(sock, buf, 1024, 0,(struct sockaddr *)&server_addr, sizeof(server_addr));printf("sendto 198.18.36.1 ret:%d\n", ret);usleep(200000);}close(sock);return 0;
}

服务端udp_service.c

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <linux/sockios.h>
#include <sys/ioctl.h>#include <arpa/inet.h>
#include <errno.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <netinet/in.h>
#include <netpacket/packet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>#define BUF_SIZE    1024
#define INTERFAXENAME "mgbe3_0.14"int sock;int main(int argc, char *argv[])
{int ret = 0;char buf[1024];memset(buf,1,1024);if ( (sock=socket(AF_INET, SOCK_DGRAM, 0)) <0){perror("socket");exit(1);}struct ifreq interface;strncpy(interface.ifr_ifrn.ifrn_name, INTERFAXENAME, sizeof(INTERFAXENAME));if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, (char *)&interface, sizeof(interface))  < 0)  // 绑定vlan网卡设备{perror("SO_BINDTODEVICE failed");}struct sockaddr_in server_addr;memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(31004);server_addr.sin_addr.s_addr = inet_addr("198.16.37.4");ret = bind(sock, (struct sockaddr *)&server_addr, sizeof(server_addr));if (ret < 0) {printf("%s: bind 198.16.37.4 failed\n", __FUNCTION__);close(sock);return 0;}elseprintf("bind 198.16.37.4 success \r\n");struct sockaddr_in client_addr;socklen_t	len;len = sizeof(client_addr);while(1){ret = recvfrom(sock, buf, 1024, 0,(struct sockaddr *)&client_addr, &len);printf("recvfrom 198.16.37.3 ret:%d\n", ret);}close(sock);return 0;
}

将两个程序编译成二进制执行程序，放到开发板运行，就行测试。