try to match hostnames when clash dns used

clash/tests/data/config/rules.yaml

@@ -6,7 +6,7 @@ mixed-port: 8899
 tun:
  enable: true
  device-id: "dev://utun1989"
- route-all: true
+ route-all: false
  gateway: "198.19.0.1/32"
  so-mark: 3389
  # routes:
@@ -53,7 +53,7 @@ dns:
 
 allow-lan: true
 mode: rule
-log-level: debug
+log-level: trace
 external-controller: :9090
 external-ui: "public"
 # secret: "clash-rs"

clash_lib/src/app/dispatcher/dispatcher_impl.rs

@@ -10,7 +10,7 @@ use crate::{
  internal::proxy::{PROXY_DIRECT, PROXY_GLOBAL},
  },
  proxy::{datagram::UdpPacket, AnyInboundDatagram},
- session::Session,
+ session::{Session, SocksAddr},
 };
 use futures::{SinkExt, StreamExt};
 use std::{
@@ -75,40 +75,51 @@ impl Dispatcher {
  }
 
  #[instrument(skip(self, sess, lhs))]
- pub async fn dispatch_stream<S>(&self, sess: Session, mut lhs: S)
+ pub async fn dispatch_stream<S>(&self, mut sess: Session, mut lhs: S)
  where
  S: AsyncRead + AsyncWrite + Unpin + Send,
  {
- let sess = if self.resolver.fake_ip_enabled() {
- match sess.destination {
- crate::session::SocksAddr::Ip(addr) => {
- let ip = addr.ip();
+ let dest: SocksAddr = match &sess.destination {
+ crate::session::SocksAddr::Ip(socket_addr) => {
+ if self.resolver.fake_ip_enabled() {
+ trace!("looking up fake ip: {}", socket_addr.ip());
+ let ip = socket_addr.ip();
  if self.resolver.is_fake_ip(ip).await {
  let host = self.resolver.reverse_lookup(ip).await;
  match host {
- Some(host) => {
- let mut sess = sess;
- sess.destination = crate::session::SocksAddr::Domain(
- host,
- addr.port(),
- );
- sess
- }
+ Some(host) => (host, socket_addr.port())
+ .try_into()
+ .expect("must be valid domain"),
  None => {
  error!("failed to reverse lookup fake ip: {}", ip);
  return;
  }
  }
  } else {
- sess
+ (*socket_addr).into()
+ }
+ } else {
+ trace!("looking up resolve cache ip: {}", socket_addr.ip());
+ if let Some(resolved) =
+ self.resolver.cached_for(socket_addr.ip()).await
+ {
+ (resolved, socket_addr.port())
+ .try_into()
+ .expect("must be valid domain")
+ } else {
+ (*socket_addr).into()
  }
  }
- crate::session::SocksAddr::Domain(..) => sess,
  }
- } else {
- sess
+ crate::session::SocksAddr::Domain(host, port) => {
+ (host.to_owned(), *port)
+ .try_into()
+ .expect("must be valid domain")
+ }
  };
 
+ sess.destination = dest.clone();
+
  let mode = *self.mode.lock().unwrap();
  let (outbound_name, rule) = match mode {
  RunMode::Global => (PROXY_GLOBAL, None),
@@ -253,28 +264,17 @@ impl Dispatcher {
  while let Some(packet) = local_r.next().await {
  let mut sess = sess.clone();
  sess.source = packet.src_addr.clone().must_into_socket_addr();
- sess.destination = packet.dst_addr.clone();
-
- // populate fake ip for route matching
- let sess = if resolver.fake_ip_enabled() {
- trace!("looking up fake ip for {sess}");
- match sess.destination {
- crate::session::SocksAddr::Ip(addr) => {
- let ip = addr.ip();
+
+ let dest: SocksAddr = match &packet.dst_addr {
+ crate::session::SocksAddr::Ip(socket_addr) => {
+ if resolver.fake_ip_enabled() {
+ let ip = socket_addr.ip();
  if resolver.is_fake_ip(ip).await {
- trace!("fake ip detected");
  let host = resolver.reverse_lookup(ip).await;
  match host {
- Some(host) => {
- trace!("fake ip resolved to {}", host);
- let mut sess = sess;
- sess.destination =
- crate::session::SocksAddr::Domain(
- host,
- addr.port(),
- );
- sess
- }
+ Some(host) => (host, socket_addr.port())
+ .try_into()
+ .expect("must be valid domain"),
  None => {
  error!(
  "failed to reverse lookup fake ip: {}",
@@ -284,18 +284,31 @@ impl Dispatcher {
  }
  }
  } else {
- sess
+ (*socket_addr).into()
+ }
+ } else {
+ if let Some(resolved) =
+ resolver.cached_for(socket_addr.ip()).await
+ {
+ (resolved, socket_addr.port())
+ .try_into()
+ .expect("must be valid domain")
+ } else {
+ (*socket_addr).into()
  }
  }
- crate::session::SocksAddr::Domain(..) => sess,
  }
- } else {
- sess
+ crate::session::SocksAddr::Domain(host, port) => {
+ (host.to_owned(), *port)
+ .try_into()
+ .expect("must be valid domain")
+ }
  };
+ sess.destination = dest.clone();
 
  // mutate packet for fake ip
  let mut packet = packet;
- packet.dst_addr = sess.destination.clone();
+ packet.dst_addr = dest;
 
  let mode = *mode.lock().unwrap();
 

clash_lib/src/app/dns/mod.rs

@@ -63,6 +63,9 @@ pub trait ClashResolver: Sync + Send {
  enhanced: bool,
  ) -> anyhow::Result<Option<std::net::Ipv6Addr>>;
 
+ async fn cached_for(&self, ip: std::net::IpAddr) -> Option<String>;
+
+ /// Used for DNS Server
  async fn exchange(&self, message: op::Message) -> anyhow::Result<op::Message>;
 
  /// Only used for look up fake IP