Fix IPv6 TCP tunnel display formatting (#1980)

Normalize composite tunnel display values before rendering peer and
debug output so IPv6 tunnel types no longer append `6` to the port.

- Preserve prefixes like `txt-` while converting tunnel schemes to
  their IPv6 form.
- Recover malformed values such as `txt-tcp://...:110106` into
  `txt-tcp6://...:11010`.
- Reuse the normalized remote address display in CLI debug output.

easytier/src/proto/api.rs

@@ -149,23 +149,8 @@ pub mod instance {
             ret
         }
 
-        fn is_tunnel_ipv6(tunnel_info: &super::super::common::TunnelInfo) -> bool {
-            let Some(local_addr) = &tunnel_info.local_addr else {
-                return false;
-            };
-
-            let u: url::Url = local_addr.clone().into();
-            u.host()
-                .map(|h| matches!(h, url::Host::Ipv6(_)))
-                .unwrap_or(false)
-        }
-
         fn get_tunnel_proto_str(tunnel_info: &super::super::common::TunnelInfo) -> String {
-            if Self::is_tunnel_ipv6(tunnel_info) {
-                format!("{}6", tunnel_info.tunnel_type)
-            } else {
-                tunnel_info.tunnel_type.clone()
-            }
+            tunnel_info.display_tunnel_type()
         }
 
         pub fn get_conn_protos(&self) -> Option<Vec<String>> {

easytier/src/proto/common.proto

@@ -201,6 +201,7 @@ message TunnelInfo {
   string tunnel_type = 1;
   common.Url local_addr = 2;
   common.Url remote_addr = 3;
+  common.Url resolved_remote_addr = 4;
 }
 
 message StunInfo {

easytier/src/proto/common.rs

@@ -5,8 +5,9 @@ use std::{
 
 use anyhow::Context;
 use base64::{prelude::BASE64_STANDARD, Engine as _};
+use strum::VariantArray;
 
-use crate::tunnel::packet_def::CompressorAlgo;
+use crate::tunnel::{packet_def::CompressorAlgo, IpScheme};
 
 include!(concat!(env!("OUT_DIR"), "/common.rs"));
 
@@ -284,6 +285,105 @@ impl fmt::Display for Url {
     }
 }
 
+fn split_tunnel_scheme(raw_scheme: &str) -> Option<(&str, &'static str, bool)> {
+    for scheme in IpScheme::VARIANTS {
+        let scheme: &'static str = scheme.into();
+        if let Some(base) = raw_scheme.strip_suffix('6') {
+            if let Some(prefix) = base.strip_suffix(scheme) {
+                if prefix.is_empty() || prefix.ends_with('-') {
+                    return Some((prefix, scheme, true));
+                }
+            }
+        }
+
+        if let Some(prefix) = raw_scheme.strip_suffix(scheme) {
+            if prefix.is_empty() || prefix.ends_with('-') {
+                return Some((prefix, scheme, false));
+            }
+        }
+    }
+
+    None
+}
+
+fn normalize_tunnel_scheme(raw_scheme: &str, is_ipv6: bool) -> Option<String> {
+    let (prefix, scheme, had_ipv6_suffix) = split_tunnel_scheme(raw_scheme)?;
+    let suffix = if is_ipv6 || had_ipv6_suffix { "6" } else { "" };
+    Some(format!("{prefix}{scheme}{suffix}"))
+}
+
+fn infer_tunnel_ipv6(raw: &str) -> Option<bool> {
+    let (_, rest) = raw.split_once("://")?;
+    if rest.starts_with('[') {
+        return Some(true);
+    }
+
+    match url::Url::parse(raw).ok()?.host() {
+        Some(url::Host::Ipv4(_)) => Some(false),
+        Some(url::Host::Ipv6(_)) => Some(true),
+        Some(url::Host::Domain(_)) | None => None,
+    }
+}
+
+fn normalize_tunnel_port(raw_port: &str, is_ipv6: bool) -> Option<u16> {
+    if let Ok(port) = raw_port.parse::<u16>() {
+        return Some(port);
+    }
+
+    if is_ipv6 && raw_port.ends_with('6') {
+        return raw_port[..raw_port.len() - 1].parse::<u16>().ok();
+    }
+
+    None
+}
+
+fn normalize_tunnel_url(raw: &str, fallback_ipv6: Option<bool>) -> Option<String> {
+    let (raw_scheme, rest) = raw.split_once("://")?;
+
+    if let Some(rest) = rest.strip_prefix('[') {
+        let (host, remainder) = rest.split_once(']')?;
+        let scheme = normalize_tunnel_scheme(raw_scheme, true)?;
+
+        if remainder.is_empty() {
+            return Some(format!("{scheme}://[{host}]"));
+        }
+
+        let raw_port = remainder.strip_prefix(':')?;
+        let port = normalize_tunnel_port(raw_port, true)?;
+        return Some(format!("{scheme}://[{host}]:{port}"));
+    }
+
+    let is_ipv6 = infer_tunnel_ipv6(raw).or(fallback_ipv6).unwrap_or(false);
+    let scheme = normalize_tunnel_scheme(raw_scheme, is_ipv6)?;
+
+    if let Ok(url) = url::Url::parse(raw) {
+        let host = match url.host()? {
+            url::Host::Ipv4(host) => host.to_string(),
+            url::Host::Ipv6(host) => format!("[{host}]"),
+            url::Host::Domain(host) => host.to_string(),
+        };
+
+        return Some(match url.port_or_known_default() {
+            Some(port) => format!("{scheme}://{host}:{port}"),
+            None => format!("{scheme}://{host}"),
+        });
+    }
+
+    let (host, raw_port) = rest.rsplit_once(':')?;
+    let port = normalize_tunnel_port(raw_port, is_ipv6)?;
+    Some(format!("{scheme}://{host}:{port}"))
+}
+
+impl Url {
+    pub fn is_ipv6_tunnel_endpoint(&self) -> bool {
+        infer_tunnel_ipv6(&self.url).unwrap_or(false)
+    }
+
+    pub fn normalized_tunnel_display(&self) -> String {
+        normalize_tunnel_url(&self.url, None).unwrap_or_else(|| self.url.clone())
+    }
+}
+
 impl From<std::net::SocketAddr> for SocketAddr {
     fn from(value: std::net::SocketAddr) -> Self {
         match value {
@@ -325,6 +425,38 @@ impl Display for SocketAddr {
     }
 }
 
+impl TunnelInfo {
+    pub fn effective_remote_addr(&self) -> Option<&Url> {
+        self.resolved_remote_addr
+            .as_ref()
+            .or(self.remote_addr.as_ref())
+    }
+
+    pub fn display_tunnel_type(&self) -> String {
+        let is_ipv6 = infer_tunnel_ipv6(&self.tunnel_type).or_else(|| {
+            self.resolved_remote_addr
+                .as_ref()
+                .or(self.local_addr.as_ref())
+                .or(self.remote_addr.as_ref())
+                .map(Url::is_ipv6_tunnel_endpoint)
+        });
+
+        if self.tunnel_type.contains("://") {
+            normalize_tunnel_url(&self.tunnel_type, is_ipv6)
+                .unwrap_or_else(|| self.tunnel_type.clone())
+        } else {
+            is_ipv6
+                .and_then(|is_ipv6| normalize_tunnel_scheme(&self.tunnel_type, is_ipv6))
+                .unwrap_or_else(|| self.tunnel_type.clone())
+        }
+    }
+
+    pub fn display_remote_addr(&self) -> Option<String> {
+        self.effective_remote_addr()
+            .map(Url::normalized_tunnel_display)
+    }
+}
+
 impl TryFrom<CompressionAlgoPb> for CompressorAlgo {
     type Error = anyhow::Error;
 
@@ -397,3 +529,149 @@ impl SecureModeConfig {
         Ok(x25519_dalek::PublicKey::from(k))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{normalize_tunnel_url, TunnelInfo, Url};
+
+    fn assert_ipv6_tunnel_normalization(scheme: &str, port: u16) {
+        let expected = format!("{scheme}6://[2001:db8::1]:{port}");
+        assert_eq!(
+            normalize_tunnel_url(&format!("{scheme}://[2001:db8::1]:{port}"), None).as_deref(),
+            Some(expected.as_str())
+        );
+    }
+
+    #[test]
+    fn normalize_plain_ipv6_tunnel_url() {
+        let url = Url {
+            url: "tcp://[2001:db8::1]:11010".to_string(),
+        };
+
+        assert_eq!(
+            url.normalized_tunnel_display(),
+            "tcp6://[2001:db8::1]:11010"
+        );
+        assert!(url.is_ipv6_tunnel_endpoint());
+    }
+
+    #[test]
+    fn normalize_all_enabled_ipv6_tunnel_urls() {
+        assert_ipv6_tunnel_normalization("tcp", 11010);
+        assert_ipv6_tunnel_normalization("udp", 11010);
+
+        #[cfg(feature = "wireguard")]
+        assert_ipv6_tunnel_normalization("wg", 11011);
+
+        #[cfg(feature = "quic")]
+        assert_ipv6_tunnel_normalization("quic", 11012);
+
+        #[cfg(feature = "websocket")]
+        assert_ipv6_tunnel_normalization("ws", 80);
+
+        #[cfg(feature = "websocket")]
+        assert_ipv6_tunnel_normalization("wss", 443);
+
+        #[cfg(feature = "faketcp")]
+        assert_ipv6_tunnel_normalization("faketcp", 11013);
+    }
+
+    #[test]
+    fn normalize_composite_ipv6_tunnel_url() {
+        assert_eq!(
+            normalize_tunnel_url("txt-tcp://[2001:db8::1]:11010", None).as_deref(),
+            Some("txt-tcp6://[2001:db8::1]:11010")
+        );
+    }
+
+    #[test]
+    fn recover_malformed_composite_ipv6_tunnel_url() {
+        assert_eq!(
+            normalize_tunnel_url("txt-tcp://[2001:db8::1]:110106", None).as_deref(),
+            Some("txt-tcp6://[2001:db8::1]:11010")
+        );
+    }
+
+    #[test]
+    fn keep_normalized_ipv6_tunnel_url_stable() {
+        assert_eq!(
+            normalize_tunnel_url("tcp6://[2001:db8::1]:11010", None).as_deref(),
+            Some("tcp6://[2001:db8::1]:11010")
+        );
+    }
+
+    #[test]
+    fn normalize_ipv6_tunnel_url_without_explicit_port() {
+        assert_eq!(
+            normalize_tunnel_url("tcp://[2001:db8::1]", None).as_deref(),
+            Some("tcp6://[2001:db8::1]")
+        );
+    }
+
+    #[test]
+    fn keep_domain_host_unbracketed_when_ipv6_falls_back() {
+        assert_eq!(
+            normalize_tunnel_url("tcp://localhost:11010", Some(true)).as_deref(),
+            Some("tcp6://localhost:11010")
+        );
+    }
+
+    #[test]
+    fn tunnel_info_display_tunnel_type_preserves_composite_prefix() {
+        let tunnel = TunnelInfo {
+            tunnel_type: "txt-tcp://[2001:db8::2]:110106".to_string(),
+            local_addr: None,
+            remote_addr: Some(Url {
+                url: "txt://et.example.com".to_string(),
+            }),
+            resolved_remote_addr: None,
+        };
+
+        assert_eq!(
+            tunnel.display_tunnel_type(),
+            "txt-tcp6://[2001:db8::2]:11010"
+        );
+    }
+
+    #[test]
+    fn tunnel_info_display_tunnel_type_uses_remote_addr_fallback() {
+        let tunnel = TunnelInfo {
+            tunnel_type: "tcp".to_string(),
+            local_addr: None,
+            remote_addr: Some(Url {
+                url: "tcp://[2001:db8::2]:11010".to_string(),
+            }),
+            resolved_remote_addr: None,
+        };
+
+        assert_eq!(tunnel.display_tunnel_type(), "tcp6");
+        assert_eq!(
+            tunnel.display_remote_addr().as_deref(),
+            Some("tcp6://[2001:db8::2]:11010")
+        );
+    }
+
+    #[test]
+    fn tunnel_info_prefers_resolved_remote_addr() {
+        let tunnel = TunnelInfo {
+            tunnel_type: "txt-tcp".to_string(),
+            local_addr: None,
+            remote_addr: Some(Url {
+                url: "txt://et.example.com".to_string(),
+            }),
+            resolved_remote_addr: Some(Url {
+                url: "tcp://[2001:db8::3]:11010".to_string(),
+            }),
+        };
+
+        assert_eq!(tunnel.display_tunnel_type(), "txt-tcp6");
+        assert_eq!(
+            tunnel.display_remote_addr().as_deref(),
+            Some("tcp6://[2001:db8::3]:11010")
+        );
+        assert_eq!(
+            tunnel.effective_remote_addr().map(|url| url.url.as_str()),
+            Some("tcp://[2001:db8::3]:11010")
+        );
+    }
+}