file serving refactor

* do away with fs.FS usage in gemini, like the previous refactor in gopher
* remove spartan code in contrib
* standardize fsroot/urlroot string arguments to file serving handlers

1 files changed, 81 insertions, 57 deletions

diff --git a/contrib/fs/gemini.go b/contrib/fs/gemini.go
index 7549ce6..d0ad2d8 100644
--- a/contrib/fs/gemini.go
+++ b/contrib/fs/gemini.go
@@ -4,10 +4,10 @@ import (
 	"context"
 	"crypto/tls"
 	"io"
-	"io/fs"
 	"net/url"
 	"os"
 	"path"
+	"path/filepath"
 	"strings"
 	"text/template"
 
@@ -20,11 +20,15 @@ import (
 //
 // It is a middleware rather than a handler because after the upload is processed,
 // the server is still responsible for generating a response.
-func TitanUpload(approver tlsauth.Approver, rootdir string) sr.Middleware {
-	rootdir = strings.TrimSuffix(rootdir, "/")
+func TitanUpload(fsroot, urlroot string, approver tlsauth.Approver) sr.Middleware {
+	fsroot = strings.TrimSuffix(fsroot, "/")
 
 	return func(responder sr.Handler) sr.Handler {
 		handler := sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
+			if !strings.HasPrefix(request.Path, urlroot) {
+				return nil
+			}
+
 			body := gemini.GetTitanRequestBody(request)
 
 			tmpf, err := os.CreateTemp("", "titan_upload_")
@@ -40,8 +44,8 @@ func TitanUpload(approver tlsauth.Approver, rootdir string) sr.Middleware {
 			request = cloneRequest(request)
 			request.Path = strings.SplitN(request.Path, ";", 2)[0]
 
-			filepath := strings.TrimPrefix(request.Path, "/")
-			filepath = path.Join(rootdir, filepath)
+			filepath := strings.Trim(strings.TrimPrefix(request.Path, urlroot), "/")
+			filepath = path.Join(fsroot, filepath)
 			if err := os.Rename(tmpf.Name(), filepath); err != nil {
 				_ = os.Remove(tmpf.Name())
 				return gemini.PermanentFailure(err)
@@ -75,21 +79,33 @@ func cloneRequest(start *sr.Request) *sr.Request {
 	return next
 }
 
-// GeminiFileHandler builds a handler which serves up files from a file system.
+// GeminiFileHandler builds a handler which serves up files from the file system.
 //
 // It only serves responses for paths which do not correspond to directories on disk.
-func GeminiFileHandler(fileSystem fs.FS) sr.Handler {
+func GeminiFileHandler(fsroot, urlroot string) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
 	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
-		filepath, file, err := ResolveFile(request, fileSystem)
-		if err != nil {
-			return gemini.Failure(err)
+		if !strings.HasPrefix(request.Path, urlroot) {
+			return nil
 		}
+		requestpath := strings.Trim(strings.TrimPrefix(request.Path, urlroot), "/")
 
-		if file == nil {
+		fpath := filepath.Join(fsroot, requestpath)
+		if isPrivate(fpath) {
+			return nil
+		}
+		if isf, err := isFile(fpath); err != nil {
+			return gemini.Failure(err)
+		} else if !isf {
 			return nil
 		}
 
-		return gemini.Success(mediaType(filepath), file)
+		file, err := os.Open(fpath)
+		if err != nil {
+			return gemini.Failure(err)
+		}
+		return gemini.Success(mediaType(fpath), file)
 	})
 }
 
@@ -102,30 +118,48 @@ func GeminiFileHandler(fileSystem fs.FS) sr.Handler {
 //
 // When it encounters a directory path which doesn't end in a trailing slash (/) it
 // redirects to a URL with the trailing slash appended. This is necessary for relative
-// links not the directory's contents to function properly.
-//
-// It requires that files from the provided fs.FS implement fs.ReadDirFile. If they
-// don't, it will produce nil responses for any directory paths.
-func GeminiDirectoryDefault(fileSystem fs.FS, filenames ...string) sr.Handler {
+// links in the directory's contents to function properly.
+func GeminiDirectoryDefault(fsroot, urlroot string, filenames ...string) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
 	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
-		dirpath, dir, response := handleDirGemini(request, fileSystem)
-		if response != nil {
-			return response
+		if !strings.HasSuffix(request.Path, "/") {
+			u := *request.URL
+			u.Path += "/"
+			return gemini.PermanentRedirect(u.String())
 		}
-		if dir == nil {
+
+		if !strings.HasPrefix(request.Path, urlroot) {
 			return nil
 		}
-		defer func() { _ = dir.Close() }()
+		requestpath := strings.Trim(strings.TrimPrefix(request.Path, urlroot), "/")
 
-		filepath, file, err := ResolveDirectoryDefault(fileSystem, dirpath, dir, filenames)
-		if err != nil {
-			return gemini.Failure(err)
+		fpath := filepath.Join(fsroot, requestpath)
+		if isPrivate(fpath) {
+			return nil
 		}
-		if file == nil {
+		if isd, err := isDir(fpath); err != nil {
+			return gemini.Failure(err)
+		} else if !isd {
 			return nil
 		}
 
-		return gemini.Success(mediaType(filepath), file)
+		for _, fname := range filenames {
+			candidatepath := filepath.Join(fpath, fname)
+			if isf, err := isFile(candidatepath); err != nil {
+				return gemini.Failure(err)
+			} else if !isf {
+				continue
+			}
+
+			file, err := os.Open(candidatepath)
+			if err != nil {
+				return gemini.Failure(err)
+			}
+			return gemini.Success(mediaType(candidatepath), file)
+		}
+
+		return nil
 	})
 }
 
@@ -137,26 +171,36 @@ func GeminiDirectoryDefault(fileSystem fs.FS, filenames ...string) sr.Handler {
 // redirects to a URL with the trailing slash appended. This is necessary for relative
 // links not the directory's contents to function properly.
 //
-// It requires that files from the provided fs.FS implement fs.ReadDirFile. If they
-// don't, it will produce "51 Not Found" responses for any directory paths.
-//
 // The template may be nil, in which case DefaultGeminiDirectoryList is used instead. The
 // template is then processed with RenderDirectoryListing.
-func GeminiDirectoryListing(fileSystem fs.FS, template *template.Template) sr.Handler {
+func GeminiDirectoryListing(fsroot, urlroot string, template *template.Template) sr.Handler {
+	fsroot = strings.TrimRight(fsroot, "/")
+
 	return sr.HandlerFunc(func(ctx context.Context, request *sr.Request) *sr.Response {
-		dirpath, dir, response := handleDirGemini(request, fileSystem)
-		if response != nil {
-			return response
+		if !strings.HasSuffix(request.Path, "/") {
+			u := *request.URL
+			u.Path += "/"
+			return gemini.PermanentRedirect(u.String())
 		}
-		if dir == nil {
+		if !strings.HasPrefix(request.Path, urlroot) {
+			return nil
+		}
+		requestpath := strings.Trim(strings.TrimPrefix(request.Path, urlroot), "/")
+
+		fpath := filepath.Join(fsroot, requestpath)
+		if isPrivate(fpath) {
+			return nil
+		}
+		if isd, err := isDir(fpath); err != nil {
+			return gemini.Failure(err)
+		} else if !isd {
 			return nil
 		}
-		defer func() { _ = dir.Close() }()
 
 		if template == nil {
 			template = DefaultGeminiDirectoryList
 		}
-		body, err := RenderDirectoryListing(dirpath, dir, template, request.Server)
+		body, err := RenderDirectoryListing(fpath, requestpath, template, request.Server)
 		if err != nil {
 			return gemini.Failure(err)
 		}
@@ -173,23 +217,3 @@ var DefaultGeminiDirectoryList = template.Must(template.New("gemini_dirlist").Pa
 {{ end }}
 => ../
 `[1:]))
-
-func handleDirGemini(request *sr.Request, fileSystem fs.FS) (string, fs.ReadDirFile, *sr.Response) {
-	path, dir, err := ResolveDirectory(request, fileSystem)
-	if err != nil {
-		return "", nil, gemini.Failure(err)
-	}
-
-	if dir == nil {
-		return "", nil, nil
-	}
-
-	if !strings.HasSuffix(request.Path, "/") {
-		_ = dir.Close()
-		url := *request.URL
-		url.Path += "/"
-		return "", nil, gemini.PermanentRedirect(url.String())
-	}
-
-	return path, dir, nil
-}