双重探测NAT类型，用于检测某些对称网络

vnt/src/nat/stun.rs

@@ -6,8 +6,37 @@ use std::time::Duration;
 use crate::channel::punch::NatType;
 use std::net::UdpSocket;
 use stun_format::Attr;
-
 pub fn stun_test_nat(stun_servers: Vec<String>) -> io::Result<(NatType, Vec<Ipv4Addr>, u16)> {
+    let mut th = Vec::new();
+    for _ in 0..2 {
+        let stun_servers = stun_servers.clone();
+        let handle = std::thread::spawn(move || stun_test_nat0(stun_servers));
+        th.push(handle);
+    }
+    let mut nat_type = NatType::Cone;
+    let mut port_range = 0;
+    let mut hash_set = HashSet::new();
+    for x in th {
+        match x.join().unwrap() {
+            Ok((nat_type_t, ip_list_t, port_range_t)) => {
+                if nat_type_t == NatType::Symmetric {
+                    nat_type = NatType::Symmetric;
+                }
+                for x in ip_list_t {
+                    hash_set.insert(x);
+                }
+                if port_range < port_range_t {
+                    port_range = port_range_t;
+                }
+            }
+            Err(e) => {
+                log::warn!("{:?}", e);
+            }
+        }
+    }
+    Ok((nat_type, hash_set.into_iter().collect(), port_range))
+}
+pub fn stun_test_nat0(stun_servers: Vec<String>) -> io::Result<(NatType, Vec<Ipv4Addr>, u16)> {
     let udp = UdpSocket::bind("0.0.0.0:0")?;
     udp.set_read_timeout(Some(Duration::from_millis(300)))?;
     let mut nat_type = NatType::Cone;