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|
use std::{
io::{self, Result},
net::{IpAddr, SocketAddr},
thread::park_timeout,
time::Duration,
};
use ipnetwork::IpNetwork;
use pnet::{
datalink::{DataLinkReceiver, NetworkInterface},
packet::{
ethernet::{EtherTypes, EthernetPacket},
ip::{IpNextHeaderProtocol, IpNextHeaderProtocols},
ipv4::Ipv4Packet,
ipv6::Ipv6Packet,
tcp::TcpPacket,
udp::UdpPacket,
Packet,
},
};
use crate::{
network::{Connection, Protocol},
os::shared::get_datalink_channel,
};
const PACKET_WAIT_TIMEOUT: Duration = Duration::from_millis(10);
const CHANNEL_RESET_DELAY: Duration = Duration::from_millis(1000);
#[derive(Debug)]
pub struct Segment {
pub interface_name: String,
pub connection: Connection,
pub direction: Direction,
pub data_length: u128,
}
#[derive(PartialEq, Hash, Eq, Debug, Clone, PartialOrd)]
pub enum Direction {
Download,
Upload,
}
impl Direction {
pub fn new(network_interface_ips: &[IpNetwork], source: IpAddr) -> Self {
if network_interface_ips
.iter()
.any(|ip_network| ip_network.ip() == source)
{
Direction::Upload
} else {
Direction::Download
}
}
}
trait NextLevelProtocol {
fn get_next_level_protocol(&self) -> IpNextHeaderProtocol;
}
impl NextLevelProtocol for Ipv6Packet<'_> {
fn get_next_level_protocol(&self) -> IpNextHeaderProtocol {
self.get_next_header()
}
}
macro_rules! extract_transport_protocol {
( $ip_packet: ident ) => {{
match $ip_packet.get_next_level_protocol() {
IpNextHeaderProtocols::Tcp => {
let message = TcpPacket::new($ip_packet.payload())?;
(
Protocol::Tcp,
message.get_source(),
message.get_destination(),
$ip_packet.payload().len() as u128,
)
}
IpNextHeaderProtocols::Udp => {
let datagram = UdpPacket::new($ip_packet.payload())?;
(
Protocol::Udp,
datagram.get_source(),
datagram.get_destination(),
$ip_packet.payload().len() as u128,
)
}
_ => return None,
}
}};
}
pub struct Sniffer {
network_interface: NetworkInterface,
network_frames: Box<dyn DataLinkReceiver>,
dns_shown: bool,
}
impl Sniffer {
pub fn new(
network_interface: NetworkInterface,
network_frames: Box<dyn DataLinkReceiver>,
dns_shown: bool,
) -> Self {
Sniffer {
network_interface,
network_frames,
dns_shown,
}
}
pub fn next(&mut self) -> Option<Segment> {
let bytes = match self.network_frames.next() {
Ok(bytes) => bytes,
Err(err) => match err.kind() {
std::io::ErrorKind::TimedOut => {
park_timeout(PACKET_WAIT_TIMEOUT);
return None;
}
_ => {
park_timeout(CHANNEL_RESET_DELAY);
self.reset_channel().ok();
return None;
}
},
};
// See https://github.com/libpnet/libpnet/blob/master/examples/packetdump.rs
// VPN interfaces (such as utun0, utun1, etc) have POINT_TO_POINT bit set to 1
let payload_offset = if (self.network_interface.is_loopback()
|| self.network_interface.is_point_to_point())
&& cfg!(target_os = "macos")
{
// The pnet code for BPF loopback adds a zero'd out Ethernet header
14
} else {
0
};
let ip_packet = Ipv4Packet::new(&bytes[payload_offset..])?;
let version = ip_packet.get_version();
match version {
4 => Self::handle_v4(ip_packet, &self.network_interface, self.dns_shown),
6 => Self::handle_v6(
Ipv6Packet::new(&bytes[payload_offset..])?,
&self.network_interface,
),
_ => {
let pkg = EthernetPacket::new(bytes)?;
match pkg.get_ethertype() {
EtherTypes::Ipv4 => Self::handle_v4(
Ipv4Packet::new(pkg.payload())?,
&self.network_interface,
self.dns_shown,
),
EtherTypes::Ipv6 => {
Self::handle_v6(Ipv6Packet::new(pkg.payload())?, &self.network_interface)
}
_ => None,
}
}
}
}
pub fn reset_channel(&mut self) -> Result<()> {
self.network_frames = get_datalink_channel(&self.network_interface)
.map_err(|_| io::Error::new(io::ErrorKind::Other, "Interface not available"))?;
Ok(())
}
fn handle_v6(ip_packet: Ipv6Packet, network_interface: &NetworkInterface) -> Option<Segment> {
let (protocol, source_port, destination_port, data_length) =
extract_transport_protocol!(ip_packet);
let interface_name = network_interface.name.clone();
let direction = Direction::new(&network_interface.ips, ip_packet.get_source().into());
let from = SocketAddr::new(ip_packet.get_source().into(), source_port);
let to = SocketAddr::new(ip_packet.get_destination().into(), destination_port);
let connection = match direction {
Direction::Download => Connection::new(from, to.ip(), destination_port, protocol),
Direction::Upload => Connection::new(to, from.ip(), source_port, protocol),
};
Some(Segment {
interface_name,
connection,
data_length,
direction,
})
}
fn handle_v4(
ip_packet: Ipv4Packet,
network_interface: &NetworkInterface,
show_dns: bool,
) -> Option<Segment> {
let (protocol, source_port, destination_port, data_length) =
extract_transport_protocol!(ip_packet);
let interface_name = network_interface.name.clone();
let direction = Direction::new(&network_interface.ips, ip_packet.get_source().into());
let from = SocketAddr::new(ip_packet.get_source().into(), source_port);
let to = SocketAddr::new(ip_packet.get_destination().into(), destination_port);
let connection = match direction {
Direction::Download => Connection::new(from, to.ip(), destination_port, protocol),
Direction::Upload => Connection::new(to, from.ip(), source_port, protocol),
};
if !show_dns && connection.remote_socket.port == 53 {
return None;
}
Some(Segment {
interface_name,
connection,
data_length,
direction,
})
}
}
|
