c++ - 套接字接受无效的参数(C++)

我正在尝试创建一个网络服务器，该服务器将接受来自sockets(以不同的ports表示)的请求和命令。我有一些用于简单套接字通信的演示code，可以按预期方式编译和运行，但是当我运行我的演示(使用demo作为引用编写，这就是为什么有一些printf's)时，accept()失败，并显示以下内容:



任何建议/纠正表示赞赏。

这是我的代码:

#include <iostream>
#include <pthread.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#include <cstring>
#include <cstdlib>
#include <cstddef>

void perror_exit(char *message);
void thread_run();

int main(int argc, char const *argv[])
{

    int i, filepos, serving_port=0, command_port=0, thread_num=0;
    char *root_dir = (char *)malloc(sizeof(char *));

    int serv_sock=0, command_sock=0, new_sock_c, new_sock_s=0;

    struct sockaddr_in server,commands;
    struct sockaddr_in server_client,commands_client;

    struct sockaddr *serverptr=(struct sockaddr *)&server;
    struct sockaddr *commandsptr=(struct sockaddr *)&commands;

    struct sockaddr *server_clientptr=(struct sockaddr *)&server_client;
    struct sockaddr *commands_clientptr=(struct sockaddr *)&commands_client;

    socklen_t clientlen_s, clientlen_c;
    struct hostent *rem_s, *rem_c;

    socklen_t clientlen;
    if(argc != 9){
        perror("Wrong number of arguments, webServer");
        exit(1);
    }else{

        for (i=0;i<argc;i++){
            if (strcmp(argv[i],"-p") == 0){
                serving_port = atoi(argv[i+1]);
            }
        }

        for (i=0;i<argc;i++){
            if (strcmp(argv[i],"-c") == 0){
                command_port = atoi(argv[i+1]);
            }
        }

        for (i=0;i<argc;i++){
            if (strcmp(argv[i],"-t") == 0){
                thread_num = atoi(argv[i+1]);
            }
        }

        for (i=0;i<argc;i++){
            if (strcmp(argv[i],"-d") == 0){
                filepos = i+1;
                strncpy(root_dir, argv[i+1], strlen(argv[i+1])+1); //   +1 to get "\n" too, without +1 seg fault appears
            }
        }

    }

    server.sin_family = AF_INET;
    server.sin_addr.s_addr = htonl(INADDR_ANY);
    server.sin_port = htons(serving_port);

    commands.sin_family = AF_INET;
    commands.sin_addr.s_addr = htonl(INADDR_ANY);
    commands.sin_port = htons(command_port);

    if ((serv_sock = socket(AF_INET,SOCK_STREAM,0)) == -1)
    {
        perror_exit("Failed to create serving socket");
        // return -1;
    }

    if ((command_sock = socket(AF_INET,SOCK_STREAM,0)) == -1)
    {
        perror_exit("Failed to create command socket");
        // return -1;
    }

    if (bind(serv_sock, serverptr, sizeof(server)) < 0)
        perror_exit("bind");
    printf("Listening for connections to port %d\n", serving_port);

    if (bind(command_sock, commandsptr, sizeof(server)) < 0)
        perror_exit("bind");
    printf("Listening for commands to port %d\n", command_port);

    while(true)
    {
        clientlen_s = sizeof(server_client);
        clientlen_c = sizeof(commands_client);

        if ((new_sock_s = accept(serv_sock, server_clientptr, &clientlen_s)) < 0)
            perror_exit("accept (server)");

        if ((new_sock_c = accept(command_sock, commands_clientptr, &clientlen_c)) < 0)
            perror_exit("accept (commands)");

        if ((rem_s = gethostbyaddr((char *) &server_client.sin_addr.s_addr, sizeof(server_client.sin_addr.s_addr), server_client.sin_family)) == NULL) {
            herror("gethostbyaddr"); exit(1);
        }
        printf("Accepted serving connection from %s\n", rem_s->h_name);

        if ((rem_c = gethostbyaddr((char *) &commands_client.sin_addr.s_addr, sizeof(commands_client.sin_addr.s_addr), commands_client.sin_family)) == NULL) {
            herror("gethostbyaddr"); exit(1);
        }
        printf("Accepted command connection from %s\n", rem_c->h_name);


    }
    /* code */
    return 0;
}

void perror_exit(char *message)
{
    perror(message);
    exit(EXIT_FAILURE);
}


void thread_run()
{

}

最佳答案

在致电接受之前，您应该致电监听。

从accept manual:



您应该在循环之前添加:

 listen(serv_sock,5);
 listen(command_sock,5);

但是，为了在没有连接挂起时不阻止accept调用，您应该考虑使用select或poll。
这将允许在调用accept之前检查连接是否挂起

关于c++ - 套接字接受无效的参数(C++)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/50293158/