fs: Avoid equality check if lengths don't match

This reverts commit 0e87d64ffc.

LICENSE

@@ -1,51 +1,19 @@
-go-gemini is available under the terms of the MIT license:
+Copyright (c) 2020 Adnan Maolood
 
-	Copyright (c) 2020 Adnan Maolood
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
 
-	Permission is hereby granted, free of charge, to any person obtaining a copy
-	of this software and associated documentation files (the "Software"), to deal
-	in the Software without restriction, including without limitation the rights
-	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-	copies of the Software, and to permit persons to whom the Software is
-	furnished to do so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
 
-	The above copyright notice and this permission notice shall be included in all
-	copies or substantial portions of the Software.
-
-	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-	SOFTWARE.
-
-Portions of this program were taken from Go:
-
-	Copyright (c) 2009 The Go Authors. All rights reserved.
-
-	Redistribution and use in source and binary forms, with or without
-	modification, are permitted provided that the following conditions are
-	met:
-
-	   * Redistributions of source code must retain the above copyright
-	notice, this list of conditions and the following disclaimer.
-	   * Redistributions in binary form must reproduce the above
-	copyright notice, this list of conditions and the following disclaimer
-	in the documentation and/or other materials provided with the
-	distribution.
-	   * Neither the name of Google Inc. nor the names of its
-	contributors may be used to endorse or promote products derived from
-	this software without specific prior written permission.
-
-	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-	OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

LICENSE-GO

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -2,9 +2,9 @@
 
 [![godocs.io](https://godocs.io/git.sr.ht/~adnano/go-gemini?status.svg)](https://godocs.io/git.sr.ht/~adnano/go-gemini) [![builds.sr.ht status](https://builds.sr.ht/~adnano/go-gemini.svg)](https://builds.sr.ht/~adnano/go-gemini?)
 
-Package gemini implements the [Gemini protocol](https://gemini.circumlunar.space) in Go.
-
-It provides an API similar to that of net/http to make it easy to develop Gemini clients and servers.
+Package gemini implements the [Gemini protocol](https://gemini.circumlunar.space)
+in Go. It provides an API similar to that of net/http to facilitate the
+development of Gemini clients and servers.
 
 Compatible with version v0.14.3 of the Gemini specification.
 
@@ -12,6 +12,9 @@ Compatible with version v0.14.3 of the Gemini specification.
 
 	import "git.sr.ht/~adnano/go-gemini"
 
+Note that some filesystem-related functionality is only available on Go 1.16
+or later as it relies on the io/fs package.
+
 ## Examples
 
 There are a few examples provided in the examples directory.
@@ -24,3 +27,9 @@ To run an example:
 Send patches and questions to [~adnano/go-gemini-devel](https://lists.sr.ht/~adnano/go-gemini-devel).
 
 Subscribe to release announcements on [~adnano/go-gemini-announce](https://lists.sr.ht/~adnano/go-gemini-announce).
+
+## License
+
+go-gemini is licensed under the terms of the MIT license (see LICENSE).
+Portions of this library were adapted from Go and are governed by a BSD-style
+license (see LICENSE-GO). Those files are marked accordingly.

fs.go

@@ -1,3 +1,5 @@
+// +build go1.16
+
 package gemini
 
 import (
@@ -27,88 +29,22 @@ type fileServer struct {
 	fs.FS
 }
 
-func (fs fileServer) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
-	serveFile(w, r, fs, path.Clean(r.URL.Path), true)
-}
-
-// ServeContent replies to the request using the content in the
-// provided Reader. The main benefit of ServeContent over io.Copy
-// is that it sets the MIME type of the response.
-//
-// ServeContent tries to deduce the type from name's file extension.
-// The name is otherwise unused; it is never sent in the response.
-func ServeContent(w ResponseWriter, r *Request, name string, content io.Reader) {
-	serveContent(w, name, content)
-}
-
-func serveContent(w ResponseWriter, name string, content io.Reader) {
-	// Detect mimetype from file extension
-	ext := path.Ext(name)
-	mimetype := mime.TypeByExtension(ext)
-	w.SetMediaType(mimetype)
-	io.Copy(w, content)
-}
-
-// ServeFile responds to the request with the contents of the named file
-// or directory.
-//
-// If the provided file or directory name is a relative path, it is interpreted
-// relative to the current directory and may ascend to parent directories. If
-// the provided name is constructed from user input, it should be sanitized
-// before calling ServeFile.
-//
-// As a precaution, ServeFile will reject requests where r.URL.Path contains a
-// ".." path element; this protects against callers who might unsafely use
-// path.Join on r.URL.Path without sanitizing it and then use that
-// path.Join result as the name argument.
-//
-// As another special case, ServeFile redirects any request where r.URL.Path
-// ends in "/index.gmi" to the same path, without the final "index.gmi". To
-// avoid such redirects either modify the path or use ServeContent.
-//
-// Outside of those two special cases, ServeFile does not use r.URL.Path for
-// selecting the file or directory to serve; only the file or directory
-// provided in the name argument is used.
-func ServeFile(w ResponseWriter, r *Request, fsys fs.FS, name string) {
-	if containsDotDot(r.URL.Path) {
-		// Too many programs use r.URL.Path to construct the argument to
-		// serveFile. Reject the request under the assumption that happened
-		// here and ".." may not be wanted.
-		// Note that name might not contain "..", for example if code (still
-		// incorrectly) used path.Join(myDir, r.URL.Path).
-		w.WriteHeader(StatusBadRequest, "invalid URL path")
-		return
-	}
-	serveFile(w, r, fsys, name, false)
-}
-
-func containsDotDot(v string) bool {
-	if !strings.Contains(v, "..") {
-		return false
-	}
-	for _, ent := range strings.FieldsFunc(v, isSlashRune) {
-		if ent == ".." {
-			return true
-		}
-	}
-	return false
-}
-
-func isSlashRune(r rune) bool { return r == '/' || r == '\\' }
-
-func serveFile(w ResponseWriter, r *Request, fsys fs.FS, name string, redirect bool) {
+func (fsys fileServer) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
 	const indexPage = "/index.gmi"
 
+	url := path.Clean(r.URL.Path)
+
 	// Redirect .../index.gmi to .../
-	if strings.HasSuffix(r.URL.Path, indexPage) {
-		w.WriteHeader(StatusPermanentRedirect, "./")
+	if strings.HasSuffix(url, indexPage) {
+		w.WriteHeader(StatusPermanentRedirect, strings.TrimSuffix(url, "index.gmi"))
 		return
 	}
 
+	name := url
 	if name == "/" {
 		name = "."
 	} else {
-		name = strings.Trim(name, "/")
+		name = strings.TrimPrefix(name, "/")
 	}
 
 	f, err := fsys.Open(name)
@@ -125,51 +61,89 @@ func serveFile(w ResponseWriter, r *Request, fsys fs.FS, name string, redirect b
 	}
 
 	// Redirect to canonical path
-	if redirect {
-		url := r.URL.Path
+	if len(r.URL.Path) != 0 {
 		if stat.IsDir() {
-			// Add trailing slash
-			if url[len(url)-1] != '/' {
-				w.WriteHeader(StatusPermanentRedirect, path.Base(url)+"/")
+			target := url
+			if target != "/" {
+				target += "/"
+			}
+			if len(r.URL.Path) != len(target) || r.URL.Path != target {
+				w.WriteHeader(StatusPermanentRedirect, target)
 				return
 			}
-		} else {
+		} else if r.URL.Path[len(r.URL.Path)-1] == '/' {
 			// Remove trailing slash
-			if url[len(url)-1] == '/' {
-				w.WriteHeader(StatusPermanentRedirect, "../"+path.Base(url))
-				return
-			}
+			w.WriteHeader(StatusPermanentRedirect, url)
+			return
 		}
 	}
 
 	if stat.IsDir() {
-		// Redirect if the directory name doesn't end in a slash
-		url := r.URL.Path
-		if url[len(url)-1] != '/' {
-			w.WriteHeader(StatusRedirect, path.Base(url)+"/")
-			return
-		}
-
 		// Use contents of index.gmi if present
 		name = path.Join(name, indexPage)
 		index, err := fsys.Open(name)
 		if err == nil {
 			defer index.Close()
-			istat, err := index.Stat()
-			if err == nil {
-				f = index
-				stat = istat
-			}
+			f = index
+		} else {
+			// Failed to find index file
+			dirList(w, f)
+			return
 		}
 	}
 
-	if stat.IsDir() {
-		// Failed to find index file
-		dirList(w, f)
+	// Detect mimetype from file extension
+	ext := path.Ext(name)
+	mimetype := mime.TypeByExtension(ext)
+	w.SetMediaType(mimetype)
+	io.Copy(w, f)
+}
+
+// ServeFile responds to the request with the contents of the named file
+// or directory. If the provided name is constructed from user input, it
+// should be sanitized before calling ServeFile.
+func ServeFile(w ResponseWriter, fsys fs.FS, name string) {
+	const indexPage = "/index.gmi"
+
+	// Ensure name is relative
+	if name == "/" {
+		name = "."
+	} else {
+		name = strings.TrimLeft(name, "/")
+	}
+
+	f, err := fsys.Open(name)
+	if err != nil {
+		w.WriteHeader(toGeminiError(err))
+		return
+	}
+	defer f.Close()
+
+	stat, err := f.Stat()
+	if err != nil {
+		w.WriteHeader(toGeminiError(err))
 		return
 	}
 
-	serveContent(w, name, f)
+	if stat.IsDir() {
+		// Use contents of index file if present
+		name = path.Join(name, indexPage)
+		index, err := fsys.Open(name)
+		if err == nil {
+			defer index.Close()
+			f = index
+		} else {
+			// Failed to find index file
+			dirList(w, f)
+			return
+		}
+	}
+
+	// Detect mimetype from file extension
+	ext := path.Ext(name)
+	mimetype := mime.TypeByExtension(ext)
+	w.SetMediaType(mimetype)
+	io.Copy(w, f)
 }
 
 func dirList(w ResponseWriter, f fs.File) {

go.mod

@@ -1,5 +1,5 @@
 module git.sr.ht/~adnano/go-gemini
 
-go 1.16
+go 1.15
 
 require golang.org/x/net v0.0.0-20210119194325-5f4716e94777

middleware.go

@@ -31,7 +31,12 @@ func (w *logResponseWriter) SetMediaType(mediatype string) {
 
 func (w *logResponseWriter) Write(b []byte) (int, error) {
 	if !w.wroteHeader {
-		w.WriteHeader(StatusSuccess, w.mediatype)
+		meta := w.mediatype
+		if meta == "" {
+			// Use default media type
+			meta = defaultMediaType
+		}
+		w.WriteHeader(StatusSuccess, meta)
 	}
 	n, err := w.rw.Write(b)
 	w.Wrote += n

mux.go

@@ -1,3 +1,7 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE-GO file.
+
 package gemini
 
 import (

response_test.go

@@ -2,6 +2,7 @@ package gemini
 
 import (
 	"io"
+	"io/ioutil"
 	"strings"
 	"testing"
 )
@@ -91,7 +92,7 @@ func TestReadWriteResponse(t *testing.T) {
 
 	for _, test := range tests {
 		t.Logf("%#v", test.Raw)
-		resp, err := ReadResponse(io.NopCloser(strings.NewReader(test.Raw)))
+		resp, err := ReadResponse(ioutil.NopCloser(strings.NewReader(test.Raw)))
 		if err != test.Err {
 			t.Errorf("expected err = %v, got %v", test.Err, err)
 		}
@@ -105,7 +106,7 @@ func TestReadWriteResponse(t *testing.T) {
 		if resp.Meta != test.Meta {
 			t.Errorf("expected meta = %s, got %s", test.Meta, resp.Meta)
 		}
-		b, _ := io.ReadAll(resp.Body)
+		b, _ := ioutil.ReadAll(resp.Body)
 		body := string(b)
 		if body != test.Body {
 			t.Errorf("expected body = %#v, got %#v", test.Body, body)