Revert deprecation of UDS local DNS

- ref shadowsocks/shadowsocks-android#2650
- Server's builtin DNS will not use local-dns-addr

Author: zonyitoo

bin/common/validator/mod.rs

@@ -4,6 +4,8 @@
 
 use std::net::SocketAddr;
 
+#[cfg(feature = "local-dns")]
+use shadowsocks_service::local::dns::NameServerAddr;
 use shadowsocks_service::shadowsocks::{relay::socks5::Address, ManagerAddr, ServerAddr, ServerConfig};
 
 macro_rules! validate_type {
@@ -29,6 +31,11 @@ validate_type!(
     ManagerAddr,
     "should be either ip:port, domain:port or /path/to/unix.sock"
 );
+validate_type!(
+    validate_name_server_addr,
+    NameServerAddr,
+    "should be either ip:port or a path to unix domain socket"
+);
 validate_type!(validate_u64, u64, "should be unsigned integer");
 validate_type!(validate_u32, u32, "should be unsigned integer");
 

bin/sslocal.rs

@@ -142,7 +142,7 @@ fn main() {
     #[cfg(feature = "local-dns")]
     {
         app = clap_app!(@app (app)
-            (@arg LOCAL_DNS_ADDR: --("local-dns-addr") +takes_value required_if("PROTOCOL", "dns") {validator::validate_socket_addr} "Specify the address of local DNS server, send queries directly")
+            (@arg LOCAL_DNS_ADDR: --("local-dns-addr") +takes_value required_if("PROTOCOL", "dns") {validator::validate_name_server_addr} "Specify the address of local DNS server, send queries directly")
             (@arg REMOTE_DNS_ADDR: --("remote-dns-addr") +takes_value required_if("PROTOCOL", "dns") {validator::validate_address} "Specify the address of remote DNS server, send queries through shadowsocks' tunnel")
             (@arg DNS_LOCAL_ADDR: --("dns-addr") +takes_value requires_all(&["REMOTE_DNS_ADDR"]) {validator::validate_server_addr} "DNS address, listen to this address if specified")
         );
@@ -247,10 +247,10 @@ fn main() {
 
     #[cfg(feature = "local-dns")]
     {
-        use std::net::SocketAddr;
+        use shadowsocks_service::local::dns::NameServerAddr;
 
         if let Some(local_dns_addr) = matches.value_of("LOCAL_DNS_ADDR") {
-            let addr = local_dns_addr.parse::<SocketAddr>().expect("local dns address");
+            let addr = local_dns_addr.parse::<NameServerAddr>().expect("local dns address");
             config.local_dns_addr = Some(addr);
         }
 

crates/shadowsocks-service/src/config.rs

@@ -70,6 +70,8 @@ use shadowsocks::{
 use trust_dns_resolver::config::{NameServerConfig, Protocol, ResolverConfig};
 
 use crate::acl::AccessControl;
+#[cfg(feature = "local-dns")]
+use crate::local::dns::NameServerAddr;
 
 #[cfg(feature = "trust-dns")]
 #[derive(Serialize, Deserialize, Debug)]
@@ -574,7 +576,7 @@ pub struct Config {
     ///
     /// Sending DNS query directly to this address
     #[cfg(feature = "local-dns")]
-    pub local_dns_addr: Option<SocketAddr>,
+    pub local_dns_addr: Option<NameServerAddr>,
     /// Remote DNS's address
     ///
     /// Sending DNS query through proxy to this address

crates/shadowsocks-service/src/local/dns/client_cache.rs

@@ -121,7 +121,6 @@ impl DnsClientCache {
     }
 
     #[cfg(unix)]
-    #[allow(dead_code)]
     pub async fn lookup_unix_stream<P: AsRef<Path>>(&self, ns: &P, msg: Message) -> Result<Message, ProtoError> {
         let mut last_err = None;
 

crates/shadowsocks-service/src/local/dns/config.rs

@@ -0,0 +1,52 @@
+//! DNS configurations
+
+#[cfg(unix)]
+use std::{convert::Infallible, path::PathBuf};
+use std::{
+    fmt::{self, Display},
+    net::SocketAddr,
+    str::FromStr,
+};
+
+/// DNS name server address
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub enum NameServerAddr {
+    /// IP address
+    SocketAddr(SocketAddr),
+    /// Unix Domain Socket address
+    ///
+    /// Specifically used by Android, which served as a stream protocol based DNS server
+    #[cfg(unix)]
+    UnixSocketAddr(PathBuf),
+}
+
+/// Parse `NameServerAddr` error
+#[cfg(unix)]
+pub type NameServerAddrError = Infallible;
+/// Parse `NameServerAddr` error
+#[cfg(not(unix))]
+pub type NameServerAddrError = <SocketAddr as FromStr>::Err;
+
+impl FromStr for NameServerAddr {
+    type Err = NameServerAddrError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.parse::<SocketAddr>() {
+            Ok(addr) => Ok(NameServerAddr::SocketAddr(addr)),
+            #[cfg(unix)]
+            Err(..) => Ok(NameServerAddr::UnixSocketAddr(PathBuf::from(s))),
+            #[cfg(not(unix))]
+            Err(err) => Err(err),
+        }
+    }
+}
+
+impl Display for NameServerAddr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            NameServerAddr::SocketAddr(ref sa) => Display::fmt(sa, f),
+            #[cfg(unix)]
+            NameServerAddr::UnixSocketAddr(ref p) => write!(f, "{}", p.display()),
+        }
+    }
+}

crates/shadowsocks-service/src/local/dns/mod.rs

@@ -1,7 +1,8 @@
 //! Customized DNS resolver
 
-pub use self::server::Dns;
+pub use self::{config::NameServerAddr, server::Dns};
 
 mod client_cache;
+pub mod config;
 pub mod server;
 mod upstream;

crates/shadowsocks-service/src/local/dns/server.rs

@@ -36,29 +36,29 @@ use crate::{
     local::{context::ServiceContext, loadbalancing::PingBalancer},
 };
 
-use super::client_cache::DnsClientCache;
+use super::{client_cache::DnsClientCache, config::NameServerAddr};
 
 /// DNS Relay server
 pub struct Dns {
     context: Arc<ServiceContext>,
     mode: Mode,
-    local_addr: SocketAddr,
+    local_addr: Arc<NameServerAddr>,
     remote_addr: Arc<Address>,
 }
 
 impl Dns {
     /// Create a new DNS Relay server
-    pub fn new(local_addr: SocketAddr, remote_addr: Address) -> Dns {
+    pub fn new(local_addr: NameServerAddr, remote_addr: Address) -> Dns {
         let context = ServiceContext::new();
         Dns::with_context(Arc::new(context), local_addr, remote_addr)
     }
 
     /// Create with an existed `context`
-    pub fn with_context(context: Arc<ServiceContext>, local_addr: SocketAddr, remote_addr: Address) -> Dns {
+    pub fn with_context(context: Arc<ServiceContext>, local_addr: NameServerAddr, remote_addr: Address) -> Dns {
         Dns {
             context,
             mode: Mode::UdpOnly,
-            local_addr: local_addr,
+            local_addr: Arc::new(local_addr),
             remote_addr: Arc::new(remote_addr),
         }
     }
@@ -117,7 +117,7 @@ impl Dns {
                 client.clone(),
                 stream,
                 peer_addr,
-                self.local_addr,
+                self.local_addr.clone(),
                 self.remote_addr.clone(),
             ));
         }
@@ -127,7 +127,7 @@ impl Dns {
         client: Arc<DnsClient>,
         mut stream: TcpStream,
         peer_addr: SocketAddr,
-        local_addr: SocketAddr,
+        local_addr: Arc<NameServerAddr>,
         remote_addr: Arc<Address>,
     ) -> io::Result<()> {
         let mut length_buf = [0u8; 2];
@@ -168,7 +168,7 @@ impl Dns {
                 }
             };
 
-            let respond_message = match client.resolve(message, local_addr, &remote_addr).await {
+            let respond_message = match client.resolve(message, &local_addr, &remote_addr).await {
                 Ok(m) => m,
                 Err(err) => {
                     error!("dns tcp {} lookup error: {}", peer_addr, err);
@@ -237,7 +237,7 @@ impl Dns {
                 listener.clone(),
                 peer_addr,
                 message,
-                self.local_addr,
+                self.local_addr.clone(),
                 self.remote_addr.clone(),
             ));
         }
@@ -248,10 +248,10 @@ impl Dns {
         listener: Arc<UdpSocket>,
         peer_addr: SocketAddr,
         message: Message,
-        local_addr: SocketAddr,
+        local_addr: Arc<NameServerAddr>,
         remote_addr: Arc<Address>,
     ) -> io::Result<()> {
-        let respond_message = match client.resolve(message, local_addr, &remote_addr).await {
+        let respond_message = match client.resolve(message, &local_addr, &remote_addr).await {
             Ok(m) => m,
             Err(err) => {
                 error!("dns udp {} lookup failed, error: {}", peer_addr, err);
@@ -442,7 +442,12 @@ impl DnsClient {
         }
     }
 
-    async fn resolve(&self, request: Message, local_addr: SocketAddr, remote_addr: &Address) -> io::Result<Message> {
+    async fn resolve(
+        &self,
+        request: Message,
+        local_addr: &NameServerAddr,
+        remote_addr: &Address,
+    ) -> io::Result<Message> {
         let mut message = Message::new();
         message.set_id(request.id());
         message.set_recursion_desired(true);
@@ -476,7 +481,7 @@ impl DnsClient {
     async fn acl_lookup(
         &self,
         query: &Query,
-        local_addr: SocketAddr,
+        local_addr: &NameServerAddr,
         remote_addr: &Address,
     ) -> (io::Result<Message>, bool) {
         // Start querying name servers
@@ -657,7 +662,7 @@ impl DnsClient {
         }
     }
 
-    async fn lookup_local(&self, query: &Query, local_addr: SocketAddr) -> io::Result<Message> {
+    async fn lookup_local(&self, query: &Query, local_addr: &NameServerAddr) -> io::Result<Message> {
         let mut last_err = io::Error::new(ErrorKind::InvalidData, "resolve empty");
 
         for _ in 0..self.attempts {
@@ -672,34 +677,44 @@ impl DnsClient {
         Err(last_err)
     }
 
-    async fn lookup_local_inner(&self, query: &Query, local_addr: SocketAddr) -> io::Result<Message> {
+    async fn lookup_local_inner(&self, query: &Query, local_addr: &NameServerAddr) -> io::Result<Message> {
         let mut message = Message::new();
         message.set_id(thread_rng().gen());
         message.set_recursion_desired(true);
         message.add_query(query.clone());
 
-        // Query UDP then TCP
+        match *local_addr {
+            NameServerAddr::SocketAddr(ns) => {
+                // Query UDP then TCP
 
-        let udp_query =
-            self.client_cache
-                .lookup_udp_local(local_addr, message.clone(), self.context.connect_opts_ref());
-        let tcp_query = async move {
-            // Send TCP query after 500ms, because UDP will always return faster than TCP, there is no need to send queries simutaneously
-            time::sleep(Duration::from_millis(500)).await;
+                let udp_query =
+                    self.client_cache
+                        .lookup_udp_local(ns, message.clone(), self.context.connect_opts_ref());
+                let tcp_query = async move {
+                    // Send TCP query after 500ms, because UDP will always return faster than TCP, there is no need to send queries simutaneously
+                    time::sleep(Duration::from_millis(500)).await;
 
-            self.client_cache
-                .lookup_tcp_local(local_addr, message, self.context.connect_opts_ref())
-                .await
-        };
+                    self.client_cache
+                        .lookup_tcp_local(ns, message, self.context.connect_opts_ref())
+                        .await
+                };
 
-        tokio::pin!(udp_query);
-        tokio::pin!(tcp_query);
+                tokio::pin!(udp_query);
+                tokio::pin!(tcp_query);
 
-        match future::select(udp_query, tcp_query).await {
-            Either::Left((Ok(m), ..)) => Ok(m),
-            Either::Left((Err(..), next)) => next.await.map_err(From::from),
-            Either::Right((Ok(m), ..)) => Ok(m),
-            Either::Right((Err(..), next)) => next.await.map_err(From::from),
+                match future::select(udp_query, tcp_query).await {
+                    Either::Left((Ok(m), ..)) => Ok(m),
+                    Either::Left((Err(..), next)) => next.await.map_err(From::from),
+                    Either::Right((Ok(m), ..)) => Ok(m),
+                    Either::Right((Err(..), next)) => next.await.map_err(From::from),
+                }
+            }
+            #[cfg(unix)]
+            NameServerAddr::UnixSocketAddr(ref path) => self
+                .client_cache
+                .lookup_unix_stream(path, message)
+                .await
+                .map_err(From::from),
         }
     }
 }

crates/shadowsocks-service/src/local/mod.rs

@@ -82,44 +82,44 @@ pub async fn run(mut config: Config) -> io::Result<()> {
     accept_opts.tcp.recv_buffer_size = config.inbound_recv_buffer_size;
     accept_opts.tcp.nodelay = config.no_delay;
 
-    #[cfg(all(feature = "local-dns", feature = "trust-dns"))]
-    if let Some(socket_addr) = config.local_dns_addr {
-        use trust_dns_resolver::config::{NameServerConfig, Protocol, ResolverConfig};
-
-        trace!("initializing direct DNS resolver for {}", socket_addr);
-
-        let mut resolver_config = ResolverConfig::new();
-
-        resolver_config.add_name_server(NameServerConfig {
-            socket_addr,
-            protocol: Protocol::Udp,
-            tls_dns_name: None,
-            trust_nx_responses: false,
-            #[cfg(feature = "dns-over-tls")]
-            tls_config: None,
-        });
-        resolver_config.add_name_server(NameServerConfig {
-            socket_addr,
-            protocol: Protocol::Tcp,
-            tls_dns_name: None,
-            trust_nx_responses: false,
-            #[cfg(feature = "dns-over-tls")]
-            tls_config: None,
-        });
-
-        match DnsResolver::trust_dns_resolver(Some(resolver_config), config.ipv6_first).await {
-            Ok(r) => {
-                context.set_dns_resolver(Arc::new(r));
-            }
-            Err(err) => {
-                error!(
-                    "initialize DNS resolver failed, nameserver: {}, error: {}",
-                    socket_addr, err
-                );
-                return Err(err);
-            }
-        }
-    }
+    // #[cfg(all(feature = "local-dns", feature = "trust-dns"))]
+    // if let Some(socket_addr) = config.local_dns_addr {
+    //     use trust_dns_resolver::config::{NameServerConfig, Protocol, ResolverConfig};
+    //
+    //     trace!("initializing direct DNS resolver for {}", socket_addr);
+    //
+    //     let mut resolver_config = ResolverConfig::new();
+    //
+    //     resolver_config.add_name_server(NameServerConfig {
+    //         socket_addr,
+    //         protocol: Protocol::Udp,
+    //         tls_dns_name: None,
+    //         trust_nx_responses: false,
+    //         #[cfg(feature = "dns-over-tls")]
+    //         tls_config: None,
+    //     });
+    //     resolver_config.add_name_server(NameServerConfig {
+    //         socket_addr,
+    //         protocol: Protocol::Tcp,
+    //         tls_dns_name: None,
+    //         trust_nx_responses: false,
+    //         #[cfg(feature = "dns-over-tls")]
+    //         tls_config: None,
+    //     });
+    //
+    //     match DnsResolver::trust_dns_resolver(Some(resolver_config), config.ipv6_first).await {
+    //         Ok(r) => {
+    //             context.set_dns_resolver(Arc::new(r));
+    //         }
+    //         Err(err) => {
+    //             error!(
+    //                 "initialize DNS resolver failed, nameserver: {}, error: {}",
+    //                 socket_addr, err
+    //             );
+    //             return Err(err);
+    //         }
+    //     }
+    // }
 
     #[cfg(feature = "trust-dns")]
     if context.dns_resolver().is_system_resolver() {