c - C中的UDP套接字-Sendto()发送失败:参数无效

我试图以一种非常简单/基本的方式在C中实现UDP套接字。我的程序用于在终端之间发送/接收文件，每个终端上运行一个程序。我的客户机代码中的sendto()函数有问题这是我的代码：

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<arpa/inet.h>
#include<sys/socket.h>
#include <errno.h>

#define BUFFER_SIZE 512

int main(int argc, char *argv[])
{
    struct sockaddr_in client;
    int sockfd, bytes, errno, slen = sizeof(client);
    char buffer[BUFFER_SIZE];

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);

    if(sockfd == -1)
    {
        perror("Socket creation failed.");
        return 0;
    }

    client.sin_addr.s_addr = INADDR_ANY;
    client.sin_family = AF_INET;
    client.sin_port = htons( 0 );

    if( bind(sockfd, (struct sockaddr *)&client, sizeof(client)) == -1)
    {
        perror("Bind call failed.");
        return 0;
    }

    while(1)
    {
        printf("Enter message : ");
        fgets(buffer, BUFFER_SIZE, stdin);

        printf("Message: %s\n", buffer);
        bytes = sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&client, sizeof(client));

        printf("Bytes: %d\n", bytes);

        if(bytes == -1)
        {
            printf("Error number: %d", errno);
            perror("Send failed.");
            return 0;
        }

        memset(buffer,'\0', BUFFER_SIZE);

        if( recvfrom(sockfd, buffer, BUFFER_SIZE, 0, (struct sockaddr *)&client, &slen) == -1)
        {
            perror("Recieve failed.");
            return 0;
        }

        puts(buffer);
    }

    close(sockfd);

    return 0;
}

无论我在缓冲区中输入什么，对于无效参数，我总是从sendto（）中得到错误号22。我已经尝试了我遇到的每一个解决方案或调整，但似乎没有工作。

最佳答案

只需在bind（）之后添加这段代码

getsockname(sockfd, (struct sockaddr *)&client, &slen);

手册页

 DESCRIPTION
     The getsockname() function returns the current address for the specified
     socket.

     The address_len parameter should be initialized to indicate the amount of
     space pointed to by address.  On return it contains the actual size of
     the address returned (in bytes).

     The address is truncated if the buffer provided is too small.

RETURN VALUES
     The getsockname() function returns the value 0 if successful; otherwise
     the value -1 is returned and the global variable errno is set to indicate
     the error.

关于c - C中的UDP套接字-Sendto()发送失败:参数无效，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/33046967/