diff --git a/src/error.rs b/src/error.rs
index 3803243..00a73cc 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -15,6 +15,22 @@ impl From<std::io::Error> for Error {
     }
 }
 
+impl From<std::net::AddrParseError> for Error {
+    fn from(err: std::net::AddrParseError) -> Self {
+        Self {
+            message: err.to_string(),
+        }
+    }
+}
+
+impl From<smoltcp::iface::RouteTableFull> for Error {
+    fn from(err: smoltcp::iface::RouteTableFull) -> Self {
+        Self {
+            message: format!("{err:?}"),
+        }
+    }
+}
+
 impl From<&str> for Error {
     fn from(err: &str) -> Self {
         Self {
diff --git a/src/lib.rs b/src/lib.rs
index e3f869d..b09ee97 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -76,8 +76,8 @@ impl std::fmt::Display for ProxyType {
     }
 }
 
-pub fn main_entry(tun: &str, proxy: Proxy, options: Options) {
-    let mut ttp = TunToProxy::new(tun, options);
+pub fn main_entry(tun: &str, proxy: Proxy, options: Options) -> Result<(), Error> {
+    let mut ttp = TunToProxy::new(tun, options)?;
     match proxy.proxy_type {
         ProxyType::Socks5 => {
             ttp.add_connection_manager(Socks5Manager::new(proxy.addr, proxy.credentials));
@@ -86,7 +86,5 @@ pub fn main_entry(tun: &str, proxy: Proxy, options: Options) {
             ttp.add_connection_manager(HttpManager::new(proxy.addr, proxy.credentials));
         }
     }
-    if let Err(e) = ttp.run() {
-        log::error!("{e}");
-    }
+    ttp.run()
 }
diff --git a/src/main.rs b/src/main.rs
index 50a0d53..7cb0797 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -47,5 +47,7 @@ fn main() {
         options = options.with_virtual_dns();
     }
 
-    main_entry(&args.tun, args.proxy, options);
+    if let Err(e) = main_entry(&args.tun, args.proxy, options) {
+        log::error!("{e}");
+    }
 }
diff --git a/src/tun2proxy.rs b/src/tun2proxy.rs
index 64732cd..4dcf7e5 100644
--- a/src/tun2proxy.rs
+++ b/src/tun2proxy.rs
@@ -17,7 +17,7 @@ use std::convert::{From, TryFrom};
 use std::fmt::{Display, Formatter};
 use std::io::{Read, Write};
 use std::net::Shutdown::Both;
-use std::net::{IpAddr, SocketAddr};
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
 use std::os::unix::io::AsRawFd;
 use std::rc::Rc;
 use std::str::FromStr;
@@ -286,45 +286,29 @@ pub(crate) struct TunToProxy<'a> {
 }
 
 impl<'a> TunToProxy<'a> {
-    pub(crate) fn new(interface: &str, options: Options) -> Self {
-        let tun = TunTapInterface::new(interface, Medium::Ip).unwrap();
-        let poll = Poll::new().unwrap();
-        poll.registry()
-            .register(
-                &mut SourceFd(&tun.as_raw_fd()),
-                TCP_TOKEN,
-                Interest::READABLE,
-            )
-            .unwrap();
+    pub(crate) fn new(interface: &str, options: Options) -> Result<Self, Error> {
+        let tun = TunTapInterface::new(interface, Medium::Ip)?;
+        let poll = Poll::new()?;
+        poll.registry().register(
+            &mut SourceFd(&tun.as_raw_fd()),
+            TCP_TOKEN,
+            Interest::READABLE,
+        )?;
 
         let config = Config::new();
         let mut virt = VirtualTunDevice::new(tun.capabilities());
+        let gateway4: Ipv4Addr = std::net::Ipv4Addr::from_str("0.0.0.1")?;
+        let gateway6: Ipv6Addr = std::net::Ipv6Addr::from_str("::1")?;
         let mut iface = Interface::new(config, &mut virt);
         iface.update_ip_addrs(|ip_addrs| {
-            ip_addrs
-                .push(IpCidr::new(
-                    std::net::Ipv4Addr::from_str("0.0.0.1").unwrap().into(),
-                    0,
-                ))
-                .unwrap();
-            ip_addrs
-                .push(IpCidr::new(
-                    std::net::Ipv6Addr::from_str("::1").unwrap().into(),
-                    0,
-                ))
-                .unwrap()
+            ip_addrs.push(IpCidr::new(gateway4.into(), 0)).unwrap();
+            ip_addrs.push(IpCidr::new(gateway6.into(), 0)).unwrap()
         });
-        iface
-            .routes_mut()
-            .add_default_ipv4_route(std::net::Ipv4Addr::from_str("0.0.0.1").unwrap().into())
-            .unwrap();
-        iface
-            .routes_mut()
-            .add_default_ipv6_route(std::net::Ipv6Addr::from_str("::1").unwrap().into())
-            .unwrap();
+        iface.routes_mut().add_default_ipv4_route(gateway4.into())?;
+        iface.routes_mut().add_default_ipv6_route(gateway6.into())?;
         iface.set_any_ip(true);
 
-        Self {
+        let tun = Self {
             tun,
             poll,
             iface,
@@ -336,7 +320,8 @@ impl<'a> TunToProxy<'a> {
             device: virt,
             options,
             write_sockets: Default::default(),
-        }
+        };
+        Ok(tun)
     }
 
     pub(crate) fn add_connection_manager(&mut self, manager: Rc<dyn ConnectionManager>) {
diff --git a/tests/proxy.rs b/tests/proxy.rs
index fe3125f..74e1a32 100644
--- a/tests/proxy.rs
+++ b/tests/proxy.rs
@@ -146,7 +146,7 @@ mod tests {
                         }
                         Ok(Fork::Child) => {
                             prctl::set_death_signal(signal::SIGKILL as isize).unwrap(); // 9 == SIGKILL
-                            main_entry(
+                            let _ = main_entry(
                                 TUN_TEST_DEVICE,
                                 test.proxy,
                                 Options::new().with_virtual_dns(),