LWIP中基于UDP SOCKET组播功能的实现

/*******************************************************
File name: MulticastUtility.c
Description: 组播功能的实现
Author: 陈龙Jason
Version: v1.0
********************************************************/
#include "MulticastUtility.h"
#include "igmp.h"
struct udp_pcb *multicast_client_udp = NULL;
/**
* Function: multicastServerRecv
* Description: 组播服务器接收到数据后的回调函数
* @param arg 回调时传递回来的参数
* @param pcb 当前连接的PCB
* @param p   存放接收到数据的BUF
* @param addr 发送数据的IP地址
* @param port 发送数据的端口号
**/
void multicastServerRecv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port){
printf("recv remote multicast data\n\r");
}
/**
* Function: createMulticastListen
* Description: 创建组播监听端
**/
void createMulticastListen(){
struct udp_pcb *multicast_udp;
ip_addr_t multicast_addr;
err_t err_status;

//IP4_ADDR(&multicast_addr,224,1,1,210);
IP4_ADDR(&multicast_addr, 233, 233, 233, 233);
multicast_udp = udp_new();
if( !multicast_udp){
printf("create multicast udp failed\n\r");
return;
}
err_status = udp_bind(multicast_udp,&multicast_addr,6666);
if(err_status != ERR_OK){
printf("bind multicast udp failed\n\r");
return;
}
igmp_joingroup(IP_ADDR_ANY,&multicast_addr);
igmp_joingroup(&veth_netif.ip_addr,&multicast_addr);
udp_recv(multicast_udp,multicastServerRecv,NULL);
}
/**
* Function: createMulticastListen
* Description: 创建组播的客户端模式
**/
void createMulticastClient(){
int retValue = 0;
err_t err_status;
uint8_t i;
struct pbuf *udp_data_packet;
ip_addr_t ipaddr;//定义IP类型变量
udp_data_packet = pbuf_alloc(PBUF_RAW,20,PBUF_RAM);
if(!udp_data_packet){
printf("serial udp memory allocate\n\r");
}
IP4_ADDR(&ipaddr,233,233,233,233);
if(multicast_client_udp == NULL){
multicast_client_udp = udp_new();
if( !multicast_client_udp){
printf("create udp pcb failed\n\r");
return;
}
/* 先绑定udp链接 */
err_status = udp_bind(multicast_client_udp,IP_ADDR_ANY,9675);    //绑定任意地址和1233端口
if(err_status != ERR_OK){  //绑定失败
printf("serial client udp bind failed\n\r");
return ;
}
err_status = udp_connect(multicast_client_udp,&ipaddr,4002);   //与远程NTP服务器建立连接
if(err_status != ERR_OK){  //创建连接失败
printf("serial client udp create connect failed\n\r");
return;
}
udp_recv(multicast_client_udp,multicastClientRecv,NULL);
}

memset(udp_data_packet->payload,0,udp_data_packet->len);
memcpy(udp_data_packet->payload,"hello server",13);
err_status = udp_send(multicast_client_udp,udp_data_packet);
}
/**
* Function: multicastClientRecv
* Description: 组播客户端接收到数据后的回调函数
* @param arg 回调时传递回来的参数
* @param pcb 当前连接的PCB
* @param p   存放接收到数据的BUF
* @param addr 发送数据的IP地址
* @param port 发送数据的端口号
**/
void multicastClientRecv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port){
printf("udp client recv data \n\r");//在函数体中添加具体功能
}