C套接字引发错误代码22,EINVAL – 无效参数

pid_t childpid;

下面

struct sockaddr_in servaddr,clientaddr;

它失败了

connectfd = accept(listenfd,(struct sockaddr *) &clientaddr,&clientaddrlen);

错误代码22,EINVAL – 无效参数.我是C语言的新插座,我无法理解这个问题,你能帮我解决这个问题吗？

谢谢.

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h> 
#include <linux/in.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

extern int errno;

int main()
{
    int clientaddrlen,listenfd,connectfd,bytes_rcvd,listen_queue_size=1;
    short int port_no = 2000;
    char buffer[1000];
    struct sockaddr_in servaddr,clientaddr;

    printf("Server running at port #%d\n",port_no);

    // Create server socket.
    if ( (listenfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
    {
        fprintf(stderr,"Cannot create server socket! errno=%d \n",errno);
        exit(-1);
    }
    printf("Server socket created\n");

    // Bind (attach) this process to the server socket.
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(port_no);
    bind(listenfd,(struct sockaddr *) &servaddr,sizeof(servaddr));
    printf("Server socket is bound to port #%d\n",port_no);

    // Turn 'listenfd' to a listening socket. Listen queue size is 1.
    listen(listenfd,listen_queue_size);
    printf("Server listening with a queue of size %d. \n",listen_queue_size);

    // Wait for connection(s) from client(s).
    while (1)
    {
        connectfd = accept(listenfd,&clientaddrlen);
        printf("A client has connected\n");
        if (recv(connectfd,buffer,sizeof(buffer),0 ) > 0)
            printf("Received message: %s\n",buffer);
        close(connectfd);
        printf("Server closed connection to client\n");
    }

    close(listenfd);
    return 0;
}