CS3984 Computer Systems in Rust

Home

Slides

Assignments

Resources

Information

TCP Socket Call Sequence: Server

  1. Create a socket (file descriptor)

    int socket(int domain, int type, int protocol);
    • domain: protocol family
      • AF_UNIX: Unix sockets
      • AF_INET: IPv4 sockets
      • AF_INET6: IPv6 sockets
    • type: communication semantics
      • SOCK_DGRAM: UDP
      • SOCK_STREAM: TCP
      • SOCK_RAW: raw network protocol access
0

TCP Socket Call Sequence: Server

  1. Bind the socket to an address

    int bind(int sockfd, struct sockaddr *addr,
         socklen_t addrlen);
    • sockfd: socket file descriptor
    • addr, addrlen: server address and port

  2. Mark the socket as a passive socket

    int listen(int sockfd, int backlog);
    • sockfd can be now be used with accept
    • OS will queue up to backlog pending connections
1

TCP Server: Rust

Code:

let socket = SocketAddr::from(([127, 0, 0, 1], 8888));
let listener = TcpListener::bind(socket)?;
  1. Create a SocketAddr (IP address + port number)
  2. Bind a new socket to the address
2

TCP Server: Rust

Code:

let socket = SocketAddr::from(([127, 0, 0, 1], 8888));
let listener = TcpListener::bind(socket)?;

System Calls:

socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 3setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4)       = 0bind(3, {sa_family=AF_INET,         sin_port=htons(8888),         sin_addr=inet_addr("127.0.0.1")}, 16)        = 0listen(3, 128)                                        = 0

    FD 3 is a IP socket with the TCP protocol, queuing up to 128 connections

    3

    TCP Socket Call Sequence

    Server:

    1. Accept a connection on the socket

      int accept(int sockfd, struct sockaddr *addr,
           socklen_t *addrlen);
      • Blocks until a connection is pending
      • sockfd can then be reused to accept more clients

    Client:

    1. Create a socket

    2. Connect to the server

      int connect(int sockfd, struct sockaddr *addr,
            socklen_t *addrlen);
    4

    TCP Server and Client: Rust

    Server:

    let (stream, socket) = listener.accept()?;



    accept4(3, {sa_family=AF_INET,            sin_port=htons(42694),            sin_addr=inet_addr("127.0.0.1")},            [128 => 16], SOCK_CLOEXEC)                = 4

      Client:

      let socket = SocketAddr::from(([127, 0, 0, 1], 8888));
let stream = TcpStream::connect(socket)?;



      socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 3connect(3, {sa_family=AF_INET,            sin_port=htons(8888),            sin_addr=inet_addr("127.0.0.1")}, 16)     = 0
        5

        TCP Server and Client: Rust

        impl Read for TcpStream {}
impl Write for TcpStream {}

        Server:

        stream.write_all("hello!".as_bytes())?;



        recvfrom(4, "hello!", 4096, 0, NULL, NULL)    = 6

          Client:

          let mut temp = [0; 4096];
let n = stream.read(&mut temp)?;



          sendto(3, "hello!", 6, MSG_NOSIGNAL, NULL, 0) = 6
            6