diff --git a/Cargo.lock b/Cargo.lock
index 14bcf816..bbf78acb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -559,6 +559,7 @@ dependencies = [
  "futures",
  "lazy_static",
  "libc",
+ "log",
  "serde",
  "serde_json",
  "tokio",
diff --git a/Cargo.toml b/Cargo.toml
index fa18ae12..6e9abaaf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ edition = "2018"
 [dependencies]
 cfg-if = "1"
 futures = "0.3"
+log = "0.4"
 
 clap = "2"
 serde = { version = "1", features = ["derive"] }
diff --git a/src/main.rs b/src/main.rs
index a7b00cbd..3f3dd6e1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -31,8 +31,16 @@ fn start_from_conf(conf: String) {
         setup_dns(dns);
     }
 
-    let eps: Vec<Endpoint> =
-        conf.endpoints.into_iter().map(|epc| epc.build()).collect();
+    let eps: Vec<Endpoint> = conf
+        .endpoints
+        .into_iter()
+        .map(|epc| {
+            let ep = epc.build();
+            println!("inited: {}", &ep);
+            ep
+        })
+        .collect();
+
     run_relay(eps);
 }
 
diff --git a/src/relay/mod.rs b/src/relay/mod.rs
index ab7988ce..02a19a16 100644
--- a/src/relay/mod.rs
+++ b/src/relay/mod.rs
@@ -1,4 +1,4 @@
-use std::io::Result;
+use log::error;
 use futures::future::join_all;
 
 mod tcp;
@@ -17,34 +17,45 @@ pub async fn run(eps: Vec<Endpoint>) {
     join_all(workers).await;
 }
 
-async fn proxy_tcp(ep: Endpoint) -> Result<()> {
+async fn proxy_tcp(ep: Endpoint) {
     let Endpoint {
         local,
         remote,
         opts,
         ..
     } = ep;
+
     let lis = TcpListener::bind(local)
         .await
         .unwrap_or_else(|_| panic!("unable to bind {}", &local));
-    while let Ok((stream, _)) = lis.accept().await {
+
+    loop {
+        let (stream, _) = match lis.accept().await {
+            Ok(x) => x,
+            Err(ref e) => {
+                error!("failed to accept tcp connection: {}", e);
+                continue;
+            }
+        };
         tokio::spawn(tcp::proxy(stream, remote.clone(), opts));
     }
-    Ok(())
 }
 
 #[cfg(feature = "udp")]
 mod udp;
 
 #[cfg(feature = "udp")]
-async fn proxy_udp(ep: Endpoint) -> Result<()> {
+async fn proxy_udp(ep: Endpoint) {
     let Endpoint {
         local,
         remote,
         opts,
         ..
     } = ep;
-    udp::proxy(local, remote, opts).await
+
+    if let Err(ref e) = udp::proxy(local, remote, opts).await {
+        panic!("udp forward exit: {}", e);
+    }
 }
 
 fn compute_workers(workers: &[Endpoint]) -> usize {
diff --git a/src/relay/tcp.rs b/src/relay/tcp.rs
index 112b9932..6ec3fdbd 100644
--- a/src/relay/tcp.rs
+++ b/src/relay/tcp.rs
@@ -78,21 +78,22 @@ pub async fn proxy(
     let (ro, wo) = outbound.split();
 
     #[cfg(all(target_os = "linux", feature = "zero-copy"))]
-    if zero_copy {
+    let res = if zero_copy {
         use zero_copy::copy;
-        let _ = try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout));
+        try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout))
     } else {
         use normal_copy::copy;
-        let _ = try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout));
-    }
+        try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout))
+    };
 
     #[cfg(not(all(target_os = "linux", feature = "zero-copy")))]
-    {
+    let res = {
         use normal_copy::copy;
-        let _ = try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout));
-    }
+        try_join!(copy(ri, wo, timeout), copy(ro, wi, timeout))
+    };
 
-    Ok(())
+    // ignore read/write n bytes
+    res.map(|_| ())
 }
 
 mod normal_copy {
@@ -148,7 +149,7 @@ mod zero_copy {
                 if libc::pipe2(pipes.as_mut_ptr() as *mut c_int, O_NONBLOCK) < 0
                 {
                     return Err(Error::new(
-                        ErrorKind::Unsupported,
+                        ErrorKind::Other,
                         "failed to create a pipe",
                     ));
                 }
@@ -209,7 +210,7 @@ mod zero_copy {
         let mut n: usize = 0;
         let mut done = false;
 
-        'LOOP: loop {
+        let res = 'LOOP: loop {
             // read until the socket buffer is empty
             // or the pipe is filled
             timeoutfut(timeout, rx.readable()).await??;
@@ -224,7 +225,12 @@ mod zero_copy {
                         clear_readiness(rx, Interest::READABLE);
                         break;
                     }
-                    _ => break 'LOOP,
+                    _ => {
+                        break 'LOOP Err(Error::new(
+                            ErrorKind::Other,
+                            "failed to splice from tcp connection",
+                        ))
+                    }
                 }
             }
             // write until the pipe is empty
@@ -233,23 +239,26 @@ mod zero_copy {
                 match splice_n(rpipe, wfd, n) {
                     x if x > 0 => n -= x as usize,
                     x if x < 0 && is_wouldblock() => {
-                        clear_readiness(wx, Interest::WRITABLE)
+                        clear_readiness(wx, Interest::WRITABLE);
+                    }
+                    _ => {
+                        break 'LOOP Err(Error::new(
+                            ErrorKind::Other,
+                            "failed to splice to tcp connection",
+                        ))
                     }
-                    _ => break 'LOOP,
                 }
             }
             // complete
             if done {
-                break;
+                break Ok(());
             }
-        }
+        };
 
         if done {
             w.shutdown().await?;
-            Ok(())
-        } else {
-            Err(Error::new(ErrorKind::ConnectionReset, "connection reset"))
-        }
+        };
+        res
     }
 }
 
diff --git a/src/relay/udp.rs b/src/relay/udp.rs
index 59e14ffc..76e85b26 100644
--- a/src/relay/udp.rs
+++ b/src/relay/udp.rs
@@ -4,6 +4,8 @@ use std::net::SocketAddr;
 use std::sync::{Arc, RwLock};
 use std::collections::HashMap;
 
+use log::error;
+
 use tokio::net::UdpSocket;
 use tokio::time::timeout as timeoutfut;
 
@@ -25,16 +27,28 @@ pub async fn proxy(
         ..
     } = conn_opts;
     let sock_map: SockMap = Arc::new(RwLock::new(HashMap::new()));
-    let local_sock = Arc::new(UdpSocket::bind(&local).await.unwrap());
+    let local_sock = Arc::new(UdpSocket::bind(&local).await?);
     let timeout = Duration::from_secs(timeout as u64);
     let mut buf = vec![0u8; BUFFERSIZE];
 
     loop {
-        let (n, client_addr) = local_sock.recv_from(&mut buf).await?;
+        let (n, client_addr) = match local_sock.recv_from(&mut buf).await {
+            Ok(x) => x,
+            Err(ref e) => {
+                error!("failed to recv udp packet: {}", e);
+                continue;
+            }
+        };
 
-        let remote_addr = remote.to_sockaddr().await?;
+        let remote_addr = match remote.to_sockaddr().await {
+            Ok(x) => x,
+            Err(ref e) => {
+                error!("failed to resolve remote addr: {}", e);
+                continue;
+            }
+        };
 
-        // the socket associated with a unique client
+        // the old/new socket associated with a unique client
         let alloc_sock = match get_socket(&sock_map, &client_addr) {
             Some(x) => x,
             None => {
@@ -50,8 +64,12 @@ pub async fn proxy(
             }
         };
 
-        alloc_sock.send_to(&buf[..n], &remote_addr).await?;
+        if let Err(ref e) = alloc_sock.send_to(&buf[..n], &remote_addr).await {
+            error!("failed to send udp packet: {}", e);
+        }
     }
+
+    // Err(Error::new(ErrorKind::Other, "unknown error"))
 }
 
 async fn send_back(
diff --git a/src/utils/types.rs b/src/utils/types.rs
index 33cdcd22..54e3d569 100644
--- a/src/utils/types.rs
+++ b/src/utils/types.rs
@@ -1,4 +1,5 @@
 use std::io::Result;
+use std::fmt::{Formatter, Display};
 use std::net::{IpAddr, SocketAddr, ToSocketAddrs};
 
 use crate::dns;
@@ -14,6 +15,7 @@ pub enum RemoteAddr {
 
 #[derive(Clone, Copy)]
 pub struct ConnectOpts {
+    pub use_udp: bool,
     pub fast_open: bool,
     pub zero_copy: bool,
     pub tcp_timeout: usize,
@@ -23,10 +25,9 @@ pub struct ConnectOpts {
 
 #[derive(Clone)]
 pub struct Endpoint {
-    pub udp: bool,
     pub local: SocketAddr,
     pub remote: RemoteAddr,
-    pub conn_opts: ConnectOpts,
+    pub opts: ConnectOpts,
 }
 
 impl RemoteAddr {
@@ -71,7 +72,7 @@ impl Endpoint {
         local: &str,
         remote: &str,
         through: &str,
-        udp: bool,
+        use_udp: bool,
         fast_open: bool,
         zero_copy: bool,
         tcp_timeout: usize,
@@ -109,10 +110,10 @@ impl Endpoint {
         };
 
         Endpoint {
-            udp,
             local,
             remote,
-            conn_opts: ConnectOpts {
+            opts: ConnectOpts {
+                use_udp,
                 fast_open,
                 zero_copy,
                 tcp_timeout,
@@ -122,3 +123,52 @@ impl Endpoint {
         }
     }
 }
+
+impl Display for RemoteAddr {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        use RemoteAddr::*;
+        match self {
+            SocketAddr(x) => write!(f, "{}", x),
+            DomainName(addr, port) => write!(f, "{}:{}", addr, port),
+        }
+    }
+}
+
+impl Display for ConnectOpts {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        macro_rules! on_off {
+            ($x: expr) => {
+                if $x {
+                    "on"
+                } else {
+                    "off"
+                }
+            };
+        }
+        if let Some(send_through) = &self.send_through {
+            write!(f, "send-through={}, ", send_through)?;
+        }
+        write!(
+            f,
+            "udp-forward={}, tcp-fast-open={}, tcp-zero-copy={}, ",
+            on_off!(self.use_udp),
+            on_off!(self.fast_open),
+            on_off!(self.zero_copy)
+        )?;
+        write!(
+            f,
+            "tcp-timeout={}s, udp-timeout={}s",
+            self.tcp_timeout, self.udp_timeout
+        )
+    }
+}
+
+impl Display for Endpoint {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{} -> {}, options: {}",
+            &self.local, &self.remote, &self.opts
+        )
+    }
+}