Surge 5.21.1：新增 MTProto 服务器、Tailscale 自动路由

What's New

Surge as MTProto Server - Surge now can operate as an incoming MTProto proxy server for Telegram. Please read manual for more information: https://manual.nssurge.com/

Tailscale - Added interactive Tailscale sign-in on iOS and macOS. Resolve the issue where some enterprise users are unable to obtain the auth key. - Added automatic Tailscale routing. Surge can discover the tailnet’s MagicDNS suffix and peer IPv4/IPv6 addresses, then automatically route matching domains and peer IP traffic through the corresponding Tailscale policy. - Automatic Tailscale routing is enabled by default and can be disabled with `auto-add-magic-dns-rule = false`. - Improved Tailscale session warm-up and recovery. Sessions now retry MagicDNS discovery after startup failures and network changes without requiring matching traffic to arrive first. - Tailscale sessions now stay active by default. An omitted `idle-keepalive`, `0`, or `-1` keeps the session always active; set a positive value to enable idle teardown. - Tailscale can now begin handling traffic as soon as a valid network map is received, without waiting for the home DERP connection to be established. - Improved recovery after network changes and control-server reconnections by preserving the last known home DERP region and retrying peer handshakes at the appropriate time. - Aligned DERP measurement and selection behavior with official Tailscale client, improving compatibility with custom DERP maps, STUN-only nodes, fallback probes, and temporarily unavailable control connections. - Sensitive values such as authentication keys and authorization URLs are now redacted from verbose Tailscale control logs.

TLS - Added `server-cert-verify-name` to independently specify the hostname used for proxy server certificate verification without changing SNI. This parameter applies to all TLS- and QUIC-based proxy protocols.

ECN - Reworked ECN configuration and packet handling across QUIC, WireGuard, Tailscale, Ponte, and nested UDP tunnels. - Correctly preserves ECN and DSCP/TOS metadata across IPv4 and IPv6 encapsulation and decapsulation. - For QUIC-based proxy protocols, when ECN is enabled, anomalies will be automatically detected and fallback to non-ECN handling. - ECN is now enabled by default for QUIC-based proxy protocols on supported systems. WireGuard and Tailscale remain disabled by default. Use `ecn=false` or `ecn=true` to override the default explicitly. - Surge Ponte now also has ECN enabled by default, and the `client-use-ecn` parameter has been removed.

DNS - Optimized TCP connection establishment for `prefer-v4` and `prefer-v6`. In earlier versions, these two parameters indicated which record to use when a domain name had both A and AAAA records. Now, during the TCP handshake, A or AAAA records are used preferentially; if the handshake cannot be completed within 3 seconds, other records will start to be tried. - Added DNS-over-TCP support. DNS server settings now accept `tcp://hostname[:port]`.

iOS - Raised the minimum system requirement to iOS 17. - Reworked Shortcuts and App Intent support and improved the reliability of App Intent operations. - Added manual Suspend and Bypass Suspension controls. The Ponte management page, scripts, and local proxy services remain available while Surge is suspended. - Snell Server can now be configured and used on iOS and tvOS.

Codebase Refactoring

After more than a decade of development, the Surge codebase has grown into a large and complex project. To further improve reliability, we have introduced AI-assisted code review across the entire codebase.

Every code change is independently reviewed by Fable 5, GPT-5.6 Sol, and a human developer before being merged, helping us identify potential security issues, rare crash scenarios, and subtle correctness problems.

Due to the large number of updates, please refer to the Mac version release notes for details: https://nssurge.com/support/mac/release-notes