select

请教 select问题

发布于 2018-05-31 14:58:38 浏览：3566 订阅该版

7 个回答

Cheney_Chen 2018-05-31

这家伙很懒，什么也没写！

Hubert_Xie 2018-06-01

这家伙很懒，什么也没写！

Hubert_Xie 2018-07-19

这家伙很懒，什么也没写！

wandersky 2018-08-09

这家伙很懒，什么也没写！

我也发现问题了，我在调试ftp服务器的时候，由于PASV模式，使用到select然后就不正常，使用PORT模式，就没有问题。
```c
else if(str_begin_with(buf, "PASV")==0)
        {
                int dig1, dig2;
                int sockfd;
                int optval='1';//char optval='1';//willow change

session->pasv_port = 10000;
                session->pasv_active = 1;
                local.sin_port=htons(session->pasv_port);
                local.sin_addr.s_addr=INADDR_ANY;

dig1 = (int)(session->pasv_port/256);
                dig2 = session->pasv_port % 256;

FD_ZERO(&readfds);
                if((sockfd=socket(PF_INET, SOCK_STREAM, 0))==-1)
                {
                        rt_sprintf(sbuf, "425 Can't open data connection.\r\n");
                        send(session->sockfd, sbuf, strlen(sbuf), 0);
                        goto err1;
                }
                if(setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval))==-1)
                {
                        rt_sprintf(sbuf, "425 Can't open data connection.\r\n");
                        send(session->sockfd, sbuf, strlen(sbuf), 0);
                        goto err1;
                }
                if(bind(sockfd, (struct sockaddr *)&local, addr_len)==-1)
                {
                        rt_sprintf(sbuf, "425 Can't open data connection.\r\n");
                        send(session->sockfd, sbuf, strlen(sbuf), 0);
                        goto err1;
                }
                if(listen(sockfd, 1)==-1)
                {
                        rt_sprintf(sbuf, "425 Can't open data connection.\r\n");
                        send(session->sockfd, sbuf, strlen(sbuf), 0);
                        goto err1;
                }
                rt_kprintf("Listening %d seconds @ port %d\n", tv.tv_sec, session->pasv_port);
                //rt_sprintf(sbuf, "227 Entering passive mode (%d,%d,%d,%d,%d,%d)\r\n", 127, 0, 0, 1, dig1, dig2);
                rt_sprintf(sbuf, "227 Entering passive mode (%d,%d,%d,%d,%d,%d)\r\n", 0, 0, 0, 0, dig1, dig2);
                send(session->sockfd, sbuf, strlen(sbuf), 0);
                FD_SET(sockfd, &readfds);
                select(0, &readfds, 0, 0, &tv);
                if(FD_ISSET(sockfd, &readfds))
                {
                        if((session->pasv_sockfd = accept(sockfd, (struct sockaddr*)&pasvremote, &addr_len))==-1)
                        {
                                rt_sprintf(sbuf, "425 Can't open data connection.\r\n");
                                send(session->sockfd, sbuf, strlen(sbuf), 0);
                                goto err1;
                        }
                        else
                        {
                                rt_kprintf("Got Data(PASV) connection from %s\n", inet_ntoa(pasvremote.sin_addr));
                                session->pasv_active = 1;
                                closesocket(sockfd);
                        }
                }
                else
                {
err1:
                        closesocket(sockfd);//closesocket(session->pasv_sockfd);
                        session->pasv_active = 0;
                        rt_free(sbuf);
                        return 0;
                }
```
正在努力解决中。。。