c - 从 linux 上的 UDPServer 向 Windows 上的 UDPClient 发送 msg 时出现问题

Question

我有在 linux 上运行的 UDPServer 程序和在 Windows 10 上运行的 UDPClient 程序。

注意：在 UDP 客户端程序中，您必须在哈希定义中添加 linux 服务器 IP。

windows上编译：gcc -Wall -o UDPClient UDPClient.c -lws2_32

问题 UDPServer 从 UDP 客户端接收 msg 并回复。但是 Windows 上的 UDPClient 没有收到来自 Windows 的消息。

UDPServer.c（在 Linux 上）

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

#define PORT     6200 
#define MAXLINE 1024 


int main() { 
    int sockfd; 
    char buffer[MAXLINE]; 
    char *hello = "Hello from server"; 
    struct sockaddr_in servaddr, cliaddr;
    int n;
    socklen_t from_len = sizeof(struct sockaddr);
    socklen_t to_len = sizeof(struct sockaddr);

    // Creating socket file descriptor 
    if ( (sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) { 
        perror("socket creation failed"); 
        exit(EXIT_FAILURE); 
    } 

    memset(&servaddr, 0, sizeof(servaddr)); 
    memset(&cliaddr, 0, sizeof(cliaddr)); 

    // Filling server information 
    servaddr.sin_family    = AF_INET; // IPv4 
    //servaddr.sin_addr.s_addr = inet_addr(IP_ADDR); ; 
    servaddr.sin_addr.s_addr = INADDR_ANY;
    servaddr.sin_port = htons(PORT); 

    // Bind the socket with the server address 
    if ( bind(sockfd, (const struct sockaddr *)&servaddr, sizeof(servaddr)) < 0 ) 
    { 
        perror("bind failed"); 
        exit(EXIT_FAILURE); 
    } 

    n = recvfrom(sockfd, (char *)buffer, MAXLINE, 0, ( struct sockaddr *) &cliaddr, &from_len); 
    buffer[n] = '\0'; 
    printf("Client : %s ; IP = %s ; Port = %d\n", buffer,inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port));

    sendto(sockfd, (const char *)hello, strlen(hello), MSG_CONFIRM, (const struct sockaddr *) &cliaddr, to_len); 
    printf("Hello message sent.\n");  

    return 0; 
}

---

// UDP client (on windows)
#include<stdio.h>
#include<winsock2.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h> 

#define PORT     6200
#define IP_ADDR "xx.xx.xx.xx"  //Add the linux server IP
#define BUF_SIZE 1024

/* Compilation: gcc -Wall -o UDPClient UDPClient.c -lws2_32 */

int SetupWinSock()
{
    WSADATA wsa;

    //printf("SetupWinSock: Initializing socket system\n");
    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
    {
        printf("SetupWinSock: Failed. Error Code : %d",WSAGetLastError());
        return -1;
    }
    //printf("SetupWinSock: Initialization complete\n");

    return 0;
}


SOCKET CreateUDPSocket()
{
    SOCKET udpSocket;

    if((udpSocket = socket(AF_INET , SOCK_DGRAM , IPPROTO_UDP )) == INVALID_SOCKET)
    {
        printf("CreateUDPSocket: Failed to create socket : %d" , WSAGetLastError());
        return -1;
    }
    else
    {
        //printf("CreateUDPSocket: Socket creation successful\n");
    }

    return udpSocket;
}

int main() { 
    char buffer[BUF_SIZE]; 
    char *hello = "Hello from client"; 
    struct sockaddr_in servaddr, localAddr; 
        SOCKET udpSocket;
    int n, len; 

        SetupWinSock();

    // Creating socket file descriptor 
    udpSocket = CreateUDPSocket();

    memset(&servaddr, 0, sizeof(servaddr)); 

    // Server info
    servaddr.sin_family = AF_INET; 
    servaddr.sin_port = htons(PORT); 
    servaddr.sin_addr.s_addr = inet_addr(IP_ADDR); 
    // Client info
    localAddr.sin_family = AF_INET;
    localAddr.sin_port = htons(PORT);
    localAddr.sin_addr.s_addr = INADDR_ANY;

    if ( bind(udpSocket,(const struct sockaddr *)&localAddr, sizeof(localAddr)) < 0 )
    {
      printf("Failed to bind\n");
      return -1;
    }

    sendto(udpSocket, (const char *)hello, strlen(hello), 0, (const struct sockaddr *) &servaddr, sizeof(servaddr)); 
    printf("Hello message sent.\n"); 

    n = recvfrom(udpSocket, (char *)buffer, BUF_SIZE, 0, (struct sockaddr *) &servaddr, &len); 
    buffer[n] = '\0'; 
    printf("Server : %s\n", buffer);
    fflush(stdout);

        closesocket(udpSocket);
        WSACleanup();

        while(1);

    return 0; 
}

标签： clinuxwindowssocketsudp