diff --git a/clash_lib/src/session.rs b/clash_lib/src/session.rs
index be5a17399..0ada4166e 100644
--- a/clash_lib/src/session.rs
+++ b/clash_lib/src/session.rs
@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 use std::fmt::{Debug, Display, Formatter};
+use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
 use std::{
     io,
     net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
@@ -375,8 +376,6 @@ pub struct Session {
     pub source: SocketAddr,
     /// The proxy target address of a proxy connection.
     pub destination: SocksAddr,
-    /// The packet mark SO_MARK
-    pub packet_mark: Option<u32>,
     /// The bind interface
     pub iface: Option<Interface>,
 }
@@ -409,7 +408,6 @@ impl Default for Session {
             typ: Type::Http,
             source: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0),
             destination: SocksAddr::any_ipv4(),
-            packet_mark: None,
             iface: None,
         }
     }
@@ -431,7 +429,6 @@ impl Debug for Session {
             .field("network", &self.network)
             .field("source", &self.source)
             .field("destination", &self.destination)
-            .field("packet_mark", &self.packet_mark)
             .field("iface", &self.iface)
             .finish()
     }
@@ -444,7 +441,6 @@ impl Clone for Session {
             typ: self.typ,
             source: self.source,
             destination: self.destination.clone(),
-            packet_mark: self.packet_mark,
             iface: self.iface.as_ref().cloned(),
         }
     }
@@ -461,3 +457,15 @@ fn invalid_atyp() -> io::Error {
 fn insuff_bytes() -> io::Error {
     io::Error::new(io::ErrorKind::Other, "insufficient bytes")
 }
+
+
+static GLOBAL_MARK: AtomicU32 = AtomicU32::new(0);
+static ENABLE_MARK: AtomicBool = AtomicBool::new(false);
+/// get socket SO_MARK that outgoing socket should use
+pub fn get_somark() -> Option<u32> {
+    if ENABLE_MARK.load(Ordering::Relaxed) {
+        Some(GLOBAL_MARK.load(Ordering::Relaxed))
+    } else {
+        None
+    }
+}
\ No newline at end of file