Enable dns-relay only for Android

.gitignore

@@ -11,3 +11,4 @@ Cargo.lock
 /*.json
 /restart.sh
 /udp_echo_server.py
+/.idea

Cargo.toml

@@ -52,7 +52,6 @@ camellia-cfb = ["openssl"]
 single-threaded = []
 trust-dns = ["trust-dns-resolver"]
 openssl-vendored = ["openssl/vendored"]
-dns-relay = ["trust-dns-proto"]
 
 [dependencies]
 log = "0.4"
@@ -79,7 +78,6 @@ url = "2.1"
 byte_string = "1.0"
 libsodium-sys = { version = "0.2", optional = true }
 miscreant = { version = "0.5", optional = true }
-trust-dns-proto = { version = "0.19", optional = true}
 trust-dns-resolver = { version = "0.19", features = ["dns-over-rustls", "dns-over-https-rustls"], optional = true }
 hkdf = "0.8"
 hmac = "0.7"
@@ -109,6 +107,7 @@ winapi = { version = "0.3", features = ["mswsock", "winsock2"] }
 
 [target.'cfg(target_os = "android")'.dependencies]
 sendfd = "0.3"
+trust-dns-proto = "0.19"
 
 # Just for the ioctl call macro
 [target.'cfg(any(target_os = "macos", target_os = "ios", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd"))'.dependencies]

src/bin/local.rs

@@ -149,7 +149,7 @@ fn main() {
             );
     }
 
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     {
         app = app
             .arg(
@@ -168,7 +168,7 @@ fn main() {
             )
             .arg(
                 Arg::with_name("DNS_RELAY_ADDR")
-                    .long("dns-realy")
+                    .long("dns-relay")
                     .takes_value(true)
                     .default_value("127.0.0.1:5450")
                     .help("Specify the address of DNS relay (only for Android)"),
@@ -235,7 +235,7 @@ fn main() {
         }
     }
 
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     {
         use std::net::SocketAddr;
 

src/config.rs

@@ -881,13 +881,13 @@ pub struct Config {
     /// Path for local DNS resolver, only for Android
     pub local_dns_path: Option<String>,
     /// Interanl DNS's bind address
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     pub dns_relay_addr: Option<SocketAddr>,
     /// Local DNS's address
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     pub local_dns_addr: Option<SocketAddr>,
     /// Remote DNS's address
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     pub remote_dns_addr: Option<SocketAddr>,
 }
 
@@ -972,11 +972,11 @@ impl Config {
             stat_path: None,
             protect_path: None,
             local_dns_path: None,
-            #[cfg(feature = "dns-relay")]
+            #[cfg(target_os = "android")]
             dns_relay_addr: None,
-            #[cfg(feature = "dns-relay")]
+            #[cfg(target_os = "android")]
             local_dns_addr: None,
-            #[cfg(feature = "dns-relay")]
+            #[cfg(target_os = "android")]
             remote_dns_addr: None,
         }
     }

src/context.rs

@@ -9,10 +9,10 @@ use std::{
     },
 };
 
-#[cfg(feature = "dns-relay")]
+#[cfg(target_os = "android")]
 use std::net::IpAddr;
 
-#[cfg(feature = "dns-relay")]
+#[cfg(target_os = "android")]
 use lru_time_cache::LruCache;
 
 use bloomfilter::Bloom;
@@ -166,7 +166,7 @@ pub struct Context {
     local_flow_statistic: ServerFlowStatistic,
 
     // For DNS relay's ACL domain name reverse lookup
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     reverse_lookup_cache: Mutex<LruCache<IpAddr, String>>,
 }
 
@@ -177,7 +177,7 @@ impl Context {
     /// Create a non-shared Context
     fn new(config: Config, server_state: SharedServerState) -> Context {
         let nonce_ppbloom = Mutex::new(PingPongBloom::new(config.config_type));
-        #[cfg(feature = "dns-relay")]
+        #[cfg(target_os = "android")]
         let reverse_lookup_cache = Mutex::new(LruCache::<IpAddr, String>::with_capacity(8192));
 
         Context {
@@ -186,7 +186,7 @@ impl Context {
             server_running: AtomicBool::new(true),
             nonce_ppbloom,
             local_flow_statistic: ServerFlowStatistic::new(),
-            #[cfg(feature = "dns-relay")]
+            #[cfg(target_os = "android")]
             reverse_lookup_cache,
         }
     }
@@ -283,7 +283,7 @@ impl Context {
     }
 
     /// Add a record to the reverse lookup cache
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     pub fn add_to_reverse_lookup_cache(&self, addr: IpAddr, qname: String) {
         let mut reverse_lookup_cache = self.reverse_lookup_cache.lock();
         reverse_lookup_cache.insert(addr, qname);
@@ -295,7 +295,7 @@ impl Context {
             // Proxy everything by default
             None => false,
             Some(ref a) => {
-                #[cfg(feature = "dns-relay")]
+                #[cfg(target_os = "android")]
                 {
                     match *target {
                         Address::SocketAddress(ref saddr) => {

src/relay/local.rs

@@ -13,7 +13,7 @@ use crate::{
     relay::{tcprelay::local::run as run_tcp, udprelay::local::run as run_udp, utils::set_nofile},
 };
 
-#[cfg(feature = "dns-relay")]
+#[cfg(target_os = "android")]
 use crate::relay::dnsrelay::run as run_dns_relay;
 
 /// Relay server running under local environment.
@@ -99,7 +99,7 @@ pub async fn run(mut config: Config, rt: Handle) -> io::Result<()> {
         vf.push(udp_fut.boxed());
     }
 
-    #[cfg(feature = "dns-relay")]
+    #[cfg(target_os = "android")]
     {
         // For Android's local resolver
         let dns_relay = run_dns_relay(context.clone());

src/relay/mod.rs

@@ -1,6 +1,6 @@
 //! Relay server in local and server side implementations.
 
-#[cfg(feature = "dns-relay")]
+#[cfg(target_os = "android")]
 pub mod dnsrelay;
 pub(crate) mod dns_resolver;
 pub(crate) mod flow;

src/relay/tcprelay/sys/unix/linux.rs

@@ -43,7 +43,7 @@ impl TcpStreamRedirExt for TcpStream {
             RedirType::Netfilter => get_original_destination_addr(self),
             RedirType::TProxy => {
                 // For TPROXY, uses getsockname() to retrieve original destination address
-                self.local_addr()?
+                self.local_addr()
             }
             _ => unreachable!("not supported tcp transparent proxy type"),
         }