diff --git a/apple/overtls/OverTlsWrapper.h b/apple/overtls/OverTlsWrapper.h
index 1e32970..bb83a42 100644
--- a/apple/overtls/OverTlsWrapper.h
+++ b/apple/overtls/OverTlsWrapper.h
@@ -12,6 +12,7 @@
 
 + (void) startWithConfig:(NSString*)filePath handler:(void (*)(int port, void *ctx))handler context:(void*)ctx;
 + (void) shutdown;
++ (void) setLogCallback:(void (*)(int verbosity, const char*, void*))cb context:(void*)ctx;
 
 @end
 
diff --git a/apple/overtls/OverTlsWrapper.m b/apple/overtls/OverTlsWrapper.m
index f37f3aa..754fdcf 100644
--- a/apple/overtls/OverTlsWrapper.m
+++ b/apple/overtls/OverTlsWrapper.m
@@ -15,11 +15,16 @@ @implementation OverTlsWrapper
 + (void)startWithConfig:(NSString *)filePath
                 handler:(void (*)(int port, void *ctx))handler
                 context:(void *)ctx {
-  over_tls_client_run(filePath.UTF8String, Info, handler, ctx);
+  over_tls_client_run(filePath.UTF8String, Trace, handler, ctx);
 }
 
 + (void)shutdown {
   over_tls_client_stop();
 }
 
++ (void) setLogCallback:(void (*)(int verbosity, const char*, void*))cb context:(void*)ctx {
+    typedef void (*p_cb)(enum ArgVerbosity, const char*, void*);
+    overtls_set_log_callback((p_cb)cb, ctx);
+}
+
 @end
diff --git a/src/api.rs b/src/api.rs
index bf035ac..479d0d3 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -48,8 +48,7 @@ unsafe fn _over_tls_client_run(
     ctx: *mut c_void,
 ) -> c_int {
     let shutdown_token = crate::CancellationToken::new();
-    {
-        let mut lock = EXITING_FLAG.lock().unwrap();
+    if let Ok(mut lock) = EXITING_FLAG.lock() {
         if lock.is_some() {
             log::error!("tun2proxy already started");
             return -1;
diff --git a/src/config.rs b/src/config.rs
index 8280545..9d979a0 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -131,11 +131,12 @@ impl Config {
     }
 
     pub fn listen_addr(&self) -> Result<SocketAddr> {
+        let unspec = std::net::IpAddr::from(Ipv4Addr::UNSPECIFIED);
         if self.is_server {
-            let f = |s: &Server| SocketAddr::new(s.listen_host.parse().unwrap(), s.listen_port);
+            let f = |s: &Server| SocketAddr::new(s.listen_host.parse().unwrap_or(unspec), s.listen_port);
             self.server.as_ref().map(f).ok_or_else(|| "Server listen address is not set".into())
         } else {
-            let f = |c: &Client| SocketAddr::new(c.listen_host.parse().unwrap(), c.listen_port);
+            let f = |c: &Client| SocketAddr::new(c.listen_host.parse().unwrap_or(unspec), c.listen_port);
             self.client.as_ref().map(f).ok_or_else(|| "Client listen address is not set".into())
         }
     }
diff --git a/src/dump_logger.rs b/src/dump_logger.rs
index 2f6a800..a8bb5fc 100644
--- a/src/dump_logger.rs
+++ b/src/dump_logger.rs
@@ -1,4 +1,4 @@
-use crate::ArgVerbosity;
+use crate::{ArgVerbosity, BoxError};
 use std::{
     os::raw::{c_char, c_void},
     sync::Mutex,
@@ -16,7 +16,11 @@ pub unsafe extern "C" fn overtls_set_log_callback(
     callback: Option<unsafe extern "C" fn(ArgVerbosity, *const c_char, *mut c_void)>,
     ctx: *mut c_void,
 ) {
-    *DUMP_CALLBACK.lock().unwrap() = Some(DumpCallback(callback, ctx));
+    if let Ok(mut cb) = DUMP_CALLBACK.lock() {
+        *cb = Some(DumpCallback(callback, ctx));
+    } else {
+        log::error!("set log callback failed");
+    }
 }
 
 #[derive(Clone)]
@@ -45,7 +49,9 @@ impl log::Log for DumpLogger {
         if self.enabled(record.metadata()) {
             let current_crate_name = env!("CARGO_CRATE_NAME");
             if record.module_path().unwrap_or("").starts_with(current_crate_name) {
-                self.do_dump_log(record);
+                if let Err(err) = self.do_dump_log(record) {
+                    log::error!("failed to dump log, error={:?}", err);
+                }
             }
         }
     }
@@ -54,7 +60,7 @@ impl log::Log for DumpLogger {
 }
 
 impl DumpLogger {
-    fn do_dump_log(&self, record: &log::Record) {
+    fn do_dump_log(&self, record: &log::Record) -> Result<(), BoxError> {
         let timestamp: chrono::DateTime<chrono::Local> = chrono::Local::now();
         let msg = format!(
             "[{} {:<5} {}] - {}",
@@ -63,12 +69,15 @@ impl DumpLogger {
             record.module_path().unwrap_or(""),
             record.args()
         );
-        let c_msg = std::ffi::CString::new(msg).unwrap();
+        let c_msg = std::ffi::CString::new(msg)?;
         let ptr = c_msg.as_ptr();
-        if let Some(cb) = DUMP_CALLBACK.lock().unwrap().clone() {
-            unsafe {
-                cb.call(record.level().into(), ptr);
+        if let Ok(cb) = DUMP_CALLBACK.lock() {
+            if let Some(cb) = cb.clone() {
+                unsafe {
+                    cb.call(record.level().into(), ptr);
+                }
             }
         }
+        Ok(())
     }
 }
diff --git a/src/error.rs b/src/error.rs
index 5cd937c..bd73d53 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -81,4 +81,6 @@ impl From<&String> for Error {
     }
 }
 
+pub type BoxError = Box<dyn std::error::Error + Send + Sync + 'static>;
+
 pub type Result<T, E = Error> = std::result::Result<T, E>;
diff --git a/src/lib.rs b/src/lib.rs
index ecc8076..6f77e34 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -20,7 +20,7 @@ use base64_wrapper::{base64_decode, base64_encode, Base64Engine};
 use bytes::BytesMut;
 pub use cmdopt::{ArgVerbosity, CmdOpt, Role};
 pub use dump_logger::overtls_set_log_callback;
-pub use error::{Error, Result};
+pub use error::{BoxError, Error, Result};
 use socks5_impl::protocol::{Address, StreamOperation};
 pub use tokio_util::sync::CancellationToken;