Address review comments

x/config/config.go

@@ -12,71 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/*
-Package config provides convenience functions to create dialer objects based on a text config.
-This is experimental and mostly for illustrative purposes at this point.
-
-Configurable transports simplifies the way you create and manage transports.
-With the [config] package, you can use [NewPacketDialer] and [NewStreamDialer] to create dialers using a simple text string.
-
-Key Benefits:
-
-  - Ease of Use: Create transports effortlessly by providing a textual configuration, reducing boilerplate code.
-  - Serialization: Easily share configurations with users or between different parts of your application, including your Go backend.
-  - Dynamic Configuration: Set your app's transport settings at runtime.
-  - DPI Evasion: Advanced nesting and configuration options help you evade Deep Packet Inspection (DPI).
-
-# Config Format
-
-The configuration string is composed of parts separated by the `|` symbol, which define nested dialers.
-For example, `A|B` means dialer `B` takes dialer `A` as its input.
-An empty string represents the direct TCP/UDP dialer, and is used as the input to the first cofigured dialer.
-
-Each dialer configuration follows a URL format, where the scheme defines the type of Dialer. Supported formats include:
-
-Shadowsocks proxy (compatible with Outline's access keys, package [shadowsocks])
-
-	ss://[USERINFO]@[HOST]:[PORT]?prefix=[PREFIX]
-
-SOCKS5 proxy (currently streams only, package [socks5])
-
-	socks5://[HOST]:[PORT]
-
-Stream split transport (streams only, package [split])
-
-It takes the length of the prefix. The stream will be split when PREFIX_LENGTH bytes are first written.
-
-	split:[PREFIX_LENGTH]
-
-TLS transport (currently streams only, package [tls])
-
-The sni parameter defines the name to be sent in the TLS SNI. It can be empty.
-The certname parameter defines what name to validate against the server certificate.
-
-	tls:sni=[SNI]&certname=[CERT_NAME]
-
-# Examples
-
-Packet splitting - To split outgoing streams on bytes 2 and 123, you can use:
-
-	split:2|split:123
-
-SOCKS5-over-TLS, with domain-fronting - To tunnel SOCKS5 over TLS, and set the SNI to decoy.example.com, while still validating against your host name, use:
-
-	tls:sni=decoy.example.com&certname=[HOST]|socks5:[HOST]:[PORT]
-
-Onion Routing with Shadowsocks - To route your traffic through three Shadowsocks servers, similar to [Onion Routing], use:
-
-	ss://[USERINFO1]@[HOST1]:[PORT1]|ss://[USERINFO2]@[HOST2]:[PORT2]|ss://[USERINFO3]@[HOST3]:[PORT3]
-
-In that case, HOST1 will be your entry node, and HOST3 will be your exit node.
-
-DPI Evasion - To add packet splitting to a Shadowsocks server for enhanced DPI evasion, use:
-
-	split:2|ss://[USERINFO]@[HOST]:[PORT]
-
-[Onion Routing]: https://en.wikipedia.org/wiki/Onion_routing
-*/
 package config
 
 import (
@@ -102,7 +37,7 @@ func parseConfigPart(oneDialerConfig string) (*url.URL, error) {
 	}
 	url, err := url.Parse(oneDialerConfig)
 	if err != nil {
-		return nil, fmt.Errorf("failed to parse config part: %w", err)
+		return nil, fmt.Errorf("part is not a valid URL: %w", err)
 	}
 	return url, nil
 }

x/config/doc.go

@@ -0,0 +1,80 @@
+// Copyright 2023 Jigsaw Operations LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package config provides convenience functions to create dialer objects based on a text config.
+This is experimental and mostly for illustrative purposes at this point.
+
+Configurable transports simplifies the way you create and manage transports.
+With the config package, you can use [NewPacketDialer] and [NewStreamDialer] to create dialers using a simple text string.
+
+Key Benefits:
+
+  - Ease of Use: Create transports effortlessly by providing a textual configuration, reducing boilerplate code.
+  - Serialization: Easily share configurations with users or between different parts of your application, including your Go backend.
+  - Dynamic Configuration: Set your app's transport settings at runtime.
+  - DPI Evasion: Advanced nesting and configuration options help you evade Deep Packet Inspection (DPI).
+
+# Config Format
+
+The configuration string is composed of parts separated by the `|` symbol, which define nested dialers.
+For example, `A|B` means dialer `B` takes dialer `A` as its input.
+An empty string represents the direct TCP/UDP dialer, and is used as the input to the first cofigured dialer.
+
+Each dialer configuration follows a URL format, where the scheme defines the type of Dialer. Supported formats include:
+
+Shadowsocks proxy (compatible with Outline's access keys, package [transport/shadowsocks])
+
+	ss://[USERINFO]@[HOST]:[PORT]?prefix=[PREFIX]
+
+SOCKS5 proxy (currently streams only, package [transport/socks5])
+
+	socks5://[HOST]:[PORT]
+
+Stream split transport (streams only, package [transport/split])
+
+It takes the length of the prefix. The stream will be split when PREFIX_LENGTH bytes are first written.
+
+	split:[PREFIX_LENGTH]
+
+TLS transport (currently streams only, package [x/tls])
+
+The sni parameter defines the name to be sent in the TLS SNI. It can be empty.
+The certname parameter defines what name to validate against the server certificate.
+
+	tls:sni=[SNI]&certname=[CERT_NAME]
+
+# Examples
+
+Packet splitting - To split outgoing streams on bytes 2 and 123, you can use:
+
+	split:2|split:123
+
+SOCKS5-over-TLS, with domain-fronting - To tunnel SOCKS5 over TLS, and set the SNI to decoy.example.com, while still validating against your host name, use:
+
+	tls:sni=decoy.example.com&certname=[HOST]|socks5:[HOST]:[PORT]
+
+Onion Routing with Shadowsocks - To route your traffic through three Shadowsocks servers, similar to [Onion Routing], use:
+
+	ss://[USERINFO1]@[HOST1]:[PORT1]|ss://[USERINFO2]@[HOST2]:[PORT2]|ss://[USERINFO3]@[HOST3]:[PORT3]
+
+In that case, HOST1 will be your entry node, and HOST3 will be your exit node.
+
+DPI Evasion - To add packet splitting to a Shadowsocks server for enhanced DPI evasion, use:
+
+	split:2|ss://[USERINFO]@[HOST]:[PORT]
+
+[Onion Routing]: https://en.wikipedia.org/wiki/Onion_routing
+*/
+package config