Preparations

cs144官网

Virtual machine setup instructions

Lab_FAQs

推荐使用：vscode + ssh 连接虚拟机

Lab Checkpoint 0: networking warmup

2.1 Fetch a Web page

$ telnet cs144.keithw.org http
Trying 104.196.238.229...
Connected to cs144.keithw.org.
Escape character is '^]'.

输入下面的内容（太慢可能会关闭，可以先输入好后复制粘贴）。

GET /hello HTTP/1.1
Host: cs144.keithw.org
Connection: close

HTTP/1.1 200 OK
Date: Fri, 28 Oct 2022 16:55:15 GMT
Server: Apache
Last-Modified: Thu, 13 Dec 2018 15:45:29 GMT
ETag: "e-57ce93446cb64"
Accept-Ranges: bytes
Content-Length: 14
Connection: close
Content-Type: text/plain

Hello, CS144!
Connection closed by foreign host.

2.3 Listening and connecting

可能出现下面的错误：

cs144@cs144vm:~/sponge/build$ netcat -v -l -p 9090
netcat: getnameinfo: Temporary failure in name resolution

The problem could be with the DNS resolver. Try updating the namespace in /etc/resolv.conf as follows.

nameserver 8.8.8.8

3.4 Writing webget

void get_URL(const string &host, const string &path) {
    // Your code here.

    // initialize variables
    TCPSocket Tsocket;
    Address addr = Address(host, "http");

    Tsocket.connect(addr);
    // Write a string, possibly blocking until all is written
    string msg = "GET " + path + " HTTP/1.1\r\n" +
                 "Host: " + host + "\r\n" +
                 "Connection: close\r\n\r\n";
    Tsocket.write(msg);
    // socket.h -> SHUT_RD/WR/RDWR，先用SHUT_WR关闭写，避免服务器等待
    Tsocket.shutdown(SHUT_WR);
    while(!Tsocket.eof()){
        cout << Tsocket.read();
    }
    Tsocket.close();
}