network: cleanup NAT code and start on IPv6 support

This commit is contained in:
Alex Zenla
2024-02-11 06:43:09 +00:00
parent efe425b346
commit 102cab32c3
10 changed files with 197 additions and 167 deletions

View File

@ -3,8 +3,8 @@ use std::{net::IpAddr, time::Duration};
use anyhow::{anyhow, Result};
use async_trait::async_trait;
use etherparse::{
Icmpv4Header, Icmpv4Type, Icmpv6Header, Icmpv6Type, IpNumber, NetSlice, PacketBuilder,
SlicedPacket,
Icmpv4Header, Icmpv4Type, Icmpv6Header, Icmpv6Type, IpNumber, Ipv4Slice, Ipv6Slice, NetSlice,
PacketBuilder, SlicedPacket,
};
use log::{debug, warn};
use smoltcp::wire::IpAddress;
@ -15,14 +15,13 @@ use tokio::{
use crate::{
icmp::{IcmpClient, IcmpProtocol, IcmpReply},
nat::{NatHandler, NatKey},
nat::{NatHandler, NatHandlerContext},
};
const ICMP_PING_TIMEOUT_SECS: u64 = 20;
const ICMP_TIMEOUT_SECS: u64 = 30;
pub struct ProxyIcmpHandler {
key: NatKey,
rx_sender: Sender<Vec<u8>>,
}
@ -40,22 +39,18 @@ enum ProxyIcmpSelect {
}
impl ProxyIcmpHandler {
pub fn new(key: NatKey, rx_sender: Sender<Vec<u8>>) -> Self {
ProxyIcmpHandler { key, rx_sender }
pub fn new(rx_sender: Sender<Vec<u8>>) -> Self {
ProxyIcmpHandler { rx_sender }
}
pub async fn spawn(
&mut self,
context: NatHandlerContext,
rx_receiver: Receiver<Vec<u8>>,
tx_sender: Sender<Vec<u8>>,
reclaim_sender: Sender<NatKey>,
) -> Result<()> {
let client = IcmpClient::new(IcmpProtocol::Icmp4)?;
let key = self.key;
tokio::spawn(async move {
if let Err(error) =
ProxyIcmpHandler::process(client, key, rx_receiver, tx_sender, reclaim_sender).await
{
if let Err(error) = ProxyIcmpHandler::process(client, rx_receiver, context).await {
warn!("processing of icmp proxy failed: {}", error);
}
});
@ -64,10 +59,8 @@ impl ProxyIcmpHandler {
async fn process(
client: IcmpClient,
key: NatKey,
mut rx_receiver: Receiver<Vec<u8>>,
tx_sender: Sender<Vec<u8>>,
reclaim_sender: Sender<NatKey>,
context: NatHandlerContext,
) -> Result<()> {
loop {
let deadline = tokio::time::sleep(Duration::from_secs(ICMP_TIMEOUT_SECS));
@ -89,107 +82,16 @@ impl ProxyIcmpHandler {
match net {
NetSlice::Ipv4(ipv4) => {
if ipv4.header().protocol() != IpNumber::ICMP {
continue;
}
let (header, payload) =
Icmpv4Header::from_slice(ipv4.payload().payload)?;
if let Icmpv4Type::EchoRequest(echo) = header.icmp_type {
let IpAddr::V4(external_ipv4) = key.external_ip.addr.into() else {
continue;
};
let Some(IcmpReply::Icmp4 {
header: _,
echo,
payload,
}) = client
.ping4(
external_ipv4,
echo.id,
echo.seq,
payload,
Duration::from_secs(ICMP_PING_TIMEOUT_SECS),
)
.await?
else {
continue;
};
let packet =
PacketBuilder::ethernet2(key.local_mac.0, key.client_mac.0);
let packet = match (key.external_ip.addr, key.client_ip.addr) {
(
IpAddress::Ipv4(external_addr),
IpAddress::Ipv4(client_addr),
) => packet.ipv4(external_addr.0, client_addr.0, 20),
_ => {
return Err(anyhow!("IP endpoint mismatch"));
}
};
let packet = packet.icmpv4_echo_reply(echo.id, echo.seq);
let mut buffer: Vec<u8> = Vec::new();
packet.write(&mut buffer, &payload)?;
if let Err(error) = tx_sender.try_send(buffer) {
debug!("failed to transmit icmp packet: {}", error);
}
}
ProxyIcmpHandler::process_ipv4(&context, ipv4, &client).await?
}
NetSlice::Ipv6(ipv6) => {
if ipv6.header().next_header() != IpNumber::ICMP {
continue;
}
let (header, payload) =
Icmpv6Header::from_slice(ipv6.payload().payload)?;
if let Icmpv6Type::EchoRequest(echo) = header.icmp_type {
let IpAddr::V6(external_ipv6) = key.external_ip.addr.into() else {
continue;
};
let Some(IcmpReply::Icmp6 {
header: _,
echo,
payload,
}) = client
.ping6(
external_ipv6,
echo.id,
echo.seq,
payload,
Duration::from_secs(ICMP_PING_TIMEOUT_SECS),
)
.await?
else {
continue;
};
let packet =
PacketBuilder::ethernet2(key.local_mac.0, key.client_mac.0);
let packet = match (key.external_ip.addr, key.client_ip.addr) {
(
IpAddress::Ipv6(external_addr),
IpAddress::Ipv6(client_addr),
) => packet.ipv6(external_addr.0, client_addr.0, 20),
_ => {
return Err(anyhow!("IP endpoint mismatch"));
}
};
let packet = packet.icmpv6_echo_reply(echo.id, echo.seq);
let mut buffer: Vec<u8> = Vec::new();
packet.write(&mut buffer, &payload)?;
if let Err(error) = tx_sender.try_send(buffer) {
debug!("failed to transmit icmp packet: {}", error);
}
}
ProxyIcmpHandler::process_ipv6(&context, ipv6, &client).await?
}
}
}
ProxyIcmpSelect::Close => {
reclaim_sender.send(key).await?;
break;
}
}
@ -197,4 +99,109 @@ impl ProxyIcmpHandler {
Ok(())
}
async fn process_ipv4(
context: &NatHandlerContext,
ipv4: &Ipv4Slice<'_>,
client: &IcmpClient,
) -> Result<()> {
if ipv4.header().protocol() != IpNumber::ICMP {
return Ok(());
}
let (header, payload) = Icmpv4Header::from_slice(ipv4.payload().payload)?;
if let Icmpv4Type::EchoRequest(echo) = header.icmp_type {
let IpAddr::V4(external_ipv4) = context.key.external_ip.addr.into() else {
return Ok(());
};
let Some(IcmpReply::Icmp4 {
header: _,
echo,
payload,
}) = client
.ping4(
external_ipv4,
echo.id,
echo.seq,
payload,
Duration::from_secs(ICMP_PING_TIMEOUT_SECS),
)
.await?
else {
return Ok(());
};
let packet =
PacketBuilder::ethernet2(context.key.local_mac.0, context.key.client_mac.0);
let packet = match (context.key.external_ip.addr, context.key.client_ip.addr) {
(IpAddress::Ipv4(external_addr), IpAddress::Ipv4(client_addr)) => {
packet.ipv4(external_addr.0, client_addr.0, 20)
}
_ => {
return Err(anyhow!("IP endpoint mismatch"));
}
};
let packet = packet.icmpv4_echo_reply(echo.id, echo.seq);
let mut buffer: Vec<u8> = Vec::new();
packet.write(&mut buffer, &payload)?;
if let Err(error) = context.try_send(buffer) {
debug!("failed to transmit icmp packet: {}", error);
}
}
Ok(())
}
async fn process_ipv6(
context: &NatHandlerContext,
ipv6: &Ipv6Slice<'_>,
client: &IcmpClient,
) -> Result<()> {
if ipv6.header().next_header() != IpNumber::ICMP {
return Ok(());
}
let (header, payload) = Icmpv6Header::from_slice(ipv6.payload().payload)?;
if let Icmpv6Type::EchoRequest(echo) = header.icmp_type {
let IpAddr::V6(external_ipv6) = context.key.external_ip.addr.into() else {
return Ok(());
};
let Some(IcmpReply::Icmp6 {
header: _,
echo,
payload,
}) = client
.ping6(
external_ipv6,
echo.id,
echo.seq,
payload,
Duration::from_secs(ICMP_PING_TIMEOUT_SECS),
)
.await?
else {
return Ok(());
};
let packet =
PacketBuilder::ethernet2(context.key.local_mac.0, context.key.client_mac.0);
let packet = match (context.key.external_ip.addr, context.key.client_ip.addr) {
(IpAddress::Ipv6(external_addr), IpAddress::Ipv6(client_addr)) => {
packet.ipv6(external_addr.0, client_addr.0, 20)
}
_ => {
return Err(anyhow!("IP endpoint mismatch"));
}
};
let packet = packet.icmpv6_echo_reply(echo.id, echo.seq);
let mut buffer: Vec<u8> = Vec::new();
packet.write(&mut buffer, &payload)?;
if let Err(error) = context.try_send(buffer) {
debug!("failed to transmit icmp packet: {}", error);
}
}
Ok(())
}
}

View File

@ -3,11 +3,11 @@ use async_trait::async_trait;
use log::warn;
use tokio::sync::mpsc::channel;
use tokio::sync::mpsc::Sender;
use crate::nat::NatHandlerContext;
use crate::proxynat::udp::ProxyUdpHandler;
use crate::nat::{NatHandler, NatHandlerFactory, NatKey, NatKeyProtocol};
use crate::nat::{NatHandler, NatHandlerFactory, NatKeyProtocol};
use self::icmp::ProxyIcmpHandler;
@ -30,18 +30,13 @@ impl ProxyNatHandlerFactory {
#[async_trait]
impl NatHandlerFactory for ProxyNatHandlerFactory {
async fn nat(
&self,
key: NatKey,
tx_sender: Sender<Vec<u8>>,
reclaim_sender: Sender<NatKey>,
) -> Option<Box<dyn NatHandler>> {
match key.protocol {
async fn nat(&self, context: NatHandlerContext) -> Option<Box<dyn NatHandler>> {
match context.key.protocol {
NatKeyProtocol::Udp => {
let (rx_sender, rx_receiver) = channel::<Vec<u8>>(4);
let mut handler = ProxyUdpHandler::new(key, rx_sender);
let mut handler = ProxyUdpHandler::new(rx_sender);
if let Err(error) = handler.spawn(rx_receiver, tx_sender, reclaim_sender).await {
if let Err(error) = handler.spawn(context, rx_receiver).await {
warn!("unable to spawn udp proxy handler: {}", error);
None
} else {
@ -51,9 +46,9 @@ impl NatHandlerFactory for ProxyNatHandlerFactory {
NatKeyProtocol::Icmp => {
let (rx_sender, rx_receiver) = channel::<Vec<u8>>(4);
let mut handler = ProxyIcmpHandler::new(key, rx_sender);
let mut handler = ProxyIcmpHandler::new(rx_sender);
if let Err(error) = handler.spawn(rx_receiver, tx_sender, reclaim_sender).await {
if let Err(error) = handler.spawn(context, rx_receiver).await {
warn!("unable to spawn icmp proxy handler: {}", error);
None
} else {

View File

@ -15,12 +15,11 @@ use tokio::{
use tokio::{sync::mpsc::Receiver, sync::mpsc::Sender};
use udp_stream::UdpStream;
use crate::nat::{NatHandler, NatKey};
use crate::nat::{NatHandler, NatHandlerContext};
const UDP_TIMEOUT_SECS: u64 = 60;
pub struct ProxyUdpHandler {
key: NatKey,
rx_sender: Sender<Vec<u8>>,
}
@ -39,31 +38,27 @@ enum ProxyUdpSelect {
}
impl ProxyUdpHandler {
pub fn new(key: NatKey, rx_sender: Sender<Vec<u8>>) -> Self {
ProxyUdpHandler { key, rx_sender }
pub fn new(rx_sender: Sender<Vec<u8>>) -> Self {
ProxyUdpHandler { rx_sender }
}
pub async fn spawn(
&mut self,
context: NatHandlerContext,
rx_receiver: Receiver<Vec<u8>>,
tx_sender: Sender<Vec<u8>>,
reclaim_sender: Sender<NatKey>,
) -> Result<()> {
let external_addr = match self.key.external_ip.addr {
let external_addr = match context.key.external_ip.addr {
IpAddress::Ipv4(addr) => {
SocketAddr::new(IpAddr::V4(addr.0.into()), self.key.external_ip.port)
SocketAddr::new(IpAddr::V4(addr.0.into()), context.key.external_ip.port)
}
IpAddress::Ipv6(addr) => {
SocketAddr::new(IpAddr::V6(addr.0.into()), self.key.external_ip.port)
SocketAddr::new(IpAddr::V6(addr.0.into()), context.key.external_ip.port)
}
};
let socket = UdpStream::connect(external_addr).await?;
let key = self.key;
tokio::spawn(async move {
if let Err(error) =
ProxyUdpHandler::process(key, socket, rx_receiver, tx_sender, reclaim_sender).await
{
if let Err(error) = ProxyUdpHandler::process(context, socket, rx_receiver).await {
warn!("processing of udp proxy failed: {}", error);
}
});
@ -71,11 +66,9 @@ impl ProxyUdpHandler {
}
async fn process(
key: NatKey,
context: NatHandlerContext,
mut socket: UdpStream,
mut rx_receiver: Receiver<Vec<u8>>,
tx_sender: Sender<Vec<u8>>,
reclaim_sender: Sender<NatKey>,
) -> Result<()> {
let mut external_buffer = vec![0u8; 2048];
@ -94,8 +87,9 @@ impl ProxyUdpHandler {
match selection {
ProxyUdpSelect::External(size) => {
let data = &external_buffer[0..size];
let packet = PacketBuilder::ethernet2(key.local_mac.0, key.client_mac.0);
let packet = match (key.external_ip.addr, key.client_ip.addr) {
let packet =
PacketBuilder::ethernet2(context.key.local_mac.0, context.key.client_mac.0);
let packet = match (context.key.external_ip.addr, context.key.client_ip.addr) {
(IpAddress::Ipv4(external_addr), IpAddress::Ipv4(client_addr)) => {
packet.ipv4(external_addr.0, client_addr.0, 20)
}
@ -106,10 +100,11 @@ impl ProxyUdpHandler {
return Err(anyhow!("IP endpoint mismatch"));
}
};
let packet = packet.udp(key.external_ip.port, key.client_ip.port);
let packet =
packet.udp(context.key.external_ip.port, context.key.client_ip.port);
let mut buffer: Vec<u8> = Vec::new();
packet.write(&mut buffer, data)?;
if let Err(error) = tx_sender.try_send(buffer) {
if let Err(error) = context.try_send(buffer) {
debug!("failed to transmit udp packet: {}", error);
}
}
@ -128,7 +123,6 @@ impl ProxyUdpHandler {
}
ProxyUdpSelect::Close => {
drop(socket);
reclaim_sender.send(key).await?;
break;
}
}