1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78

use std::net::{IpAddr, Ipv4Addr, SocketAddr};

use cross_socket::packet::ethernet::EtherType;
use cross_socket::socket::{Socket, DataLinkSocket, SocketOption, IpVersion, SocketType};
use cross_socket::packet::{PacketInfo, ip::IpNextLevelProtocol};
use cross_socket::interface::Interface;

// Send TCP SYN packets to 1.1.1.1:80 and check reply
// This example is for Unix(Linux, macOS ...) only.
// For Windows, use examples/datalink_socket/tcp_ping.rs instead.
// (Due to Winsock2 limitation.)
fn main() {
    let interface: Interface = cross_socket::interface::get_default_interface().unwrap();
    let src_ip: IpAddr = IpAddr::V4(interface.ipv4[0].addr);
    let src_socket_addr: SocketAddr = SocketAddr::new(src_ip, 53443);
    let dst_ip: IpAddr = IpAddr::V4(Ipv4Addr::new(1, 1, 1, 1));
    let dst_socket_addr: SocketAddr = SocketAddr::new(dst_ip, 80);
    let socket_option = SocketOption {
        ip_version: IpVersion::V4,
        socket_type: SocketType::Raw,
        protocol: Some(IpNextLevelProtocol::Tcp),
        timeout: None,
        ttl: None,
        non_blocking: false,
    };
    // Sender socket
    let socket: Socket = Socket::new(socket_option).unwrap();

    // Receiver socket
    // RAW SOCKET recvfrom not working for TCP. So we use DataLinkSocket instead.
    let mut listener_socket: DataLinkSocket = DataLinkSocket::new(interface, false).unwrap();

    // Create packet info
    let mut packet_info = PacketInfo::new();
    packet_info.src_ip = src_socket_addr.ip();
    packet_info.dst_ip = dst_socket_addr.ip();
    packet_info.src_port = Some(src_socket_addr.port());
    packet_info.dst_port = Some(dst_socket_addr.port());
    packet_info.ip_protocol = Some(IpNextLevelProtocol::Tcp);
    packet_info.payload = vec![0; 0];

    // Build TCP SYN packet
    let tcp_packet = cross_socket::packet::builder::build_tcp_syn_packet(packet_info);

    // Send TCP SYN packet to 1.1.1.1
    match socket.send_to(&tcp_packet, dst_socket_addr) {
        Ok(packet_len) => {
            println!("Sent {} bytes", packet_len);
        }
        Err(e) => {
            println!("Error: {}", e);
        }
    }

    // Receive packets
    println!("Waiting for TCP SYN+ACK... ");
    loop {
        match listener_socket.receive() {
            Ok(packet) => {
                let ethernet_packet = cross_socket::packet::ethernet::EthernetPacket::from_bytes(&packet);
                if ethernet_packet.ethertype != EtherType::Ipv4 {
                    continue;
                }
                let ip_packet = cross_socket::packet::ipv4::Ipv4Packet::from_bytes(&ethernet_packet.payload);
                if ip_packet.next_level_protocol != IpNextLevelProtocol::Tcp || ip_packet.source != std::net::Ipv4Addr::new(1, 1, 1, 1) {
                    continue;
                }
                println!("Received {} bytes from {}", packet.len(), ip_packet.source);
                let tcp_packet = cross_socket::packet::tcp::TcpPacket::from_bytes(&ip_packet.payload);
                println!("Packet: {:?}", tcp_packet);
                break;
            }
            Err(e) => {
                println!("Error: {}", e);
            }
        }
    }
}