In simulink, how can use the UDP receive information from another Linux target.

I have a Linux c++ code, it can work well with simulink instrumen UDP send toolbox, I can receive the data from the matlab. But when I send my data to the matlab, it can't work, does anyone can help me ?Thank you !

#include <iostream>
#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>


#define BUFFER_SIZE 1024 // buf size
int main(int argc, char *argv[])
{
	struct sockaddr_in serv_addr;  
	double recv_buf[1024]={0};

	int ret,sock_fd;
	socklen_t addr_len;
	// create two-way transmission socket
	if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
		perror("error");
	// initialize address
	memset(&serv_addr, 0, sizeof(struct sockaddr_in));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(5002);
	serv_addr.sin_addr.s_addr = inet_addr("192.168.1.101");
	// // bind the local port
	// if ((bind(sock_fd, (struct sockaddr *)&serv_addr,
	// 			sizeof(struct sockaddr_in))) < 0)
	// {
	// 	perror("bind");
	// 	return -1;
	// }
	double u[3]={1,2,3};

	while(1)
	{
		addr_len = sizeof(struct sockaddr_in);
		if((ret=recvfrom(sock_fd, recv_buf, sizeof(recv_buf),0, (struct sockaddr *)&serv_addr, &addr_len))<0)
			return -1;

        for(int i=0;i<7;i++)
        std::cout<<recv_buf[i]<<std::endl;


		if((sendto(sock_fd,u,sizeof(u),0, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr_in)))<0)
			return -1;

	}


	return 0;
}

[君明 张]

And I have try to set the matlab as the server, but it does't work, and it cann't receive information form matlab.

[君明 张]

I know why now, in simulink, it doesn't like a application. In actually, it's real two application. So I change the udp send code, I write the IP&port, it can work now.