mirror of
https://git.sr.ht/~adnano/go-gemini
synced 2024-05-14 20:46:05 +02:00
128 lines
3.4 KiB
Go
128 lines
3.4 KiB
Go
package gemini
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import (
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"io"
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"mime"
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"os"
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"path"
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)
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func init() {
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// Add Gemini mime types
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mime.AddExtensionType(".gmi", "text/gemini")
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mime.AddExtensionType(".gemini", "text/gemini")
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}
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// A FileSystem implements access to a collection of named files. The elements
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// in a file path are separated by slash ('/', U+002F) characters, regardless
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// of host operating system convention.
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type FileSystem interface {
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Open(name string) (File, error)
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}
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// A File is returned by a FileSystem's Open method and can be served by the
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// FileServer implementation.
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//
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// The methods should behave the same as those on an *os.File.
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type File interface {
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Stat() (os.FileInfo, error)
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Read([]byte) (int, error)
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Close() error
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}
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// A Dir implements FileSystem using the native file system restricted
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// to a specific directory tree.
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//
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// While the FileSystem.Open method takes '/'-separated paths, a Dir's string
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// value is a filename on the native file system, not a URL, so it is separated
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// by filepath.Separator, which isn't necessarily '/'.
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//
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// Note that Dir could expose sensitive files and directories. Dir will follow
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// symlinks pointing out of the directory tree, which can be especially
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// dangerous if serving from a directory in which users are able to create
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// arbitrary symlinks. Dir will also allow access to files and directories
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// starting with a period, which could expose sensitive directories like .git
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// or sensitive files like .htpasswd. To exclude files with a leading period,
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// remove the files/directories from the server or create a custom FileSystem
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// implementation.
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//
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// An empty Dir is treated as ".".
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type Dir string
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// Open implements FileSystem using os.Open, opening files for reading
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// rooted and relative to the directory d.
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func (d Dir) Open(name string) (File, error) {
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return os.Open(path.Join(string(d), name))
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}
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// FileServer returns a handler that serves Gemini requests with the contents
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// of the provided file system.
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//
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// To use the operating system's file system implementation, use gemini.Dir:
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//
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// gemini.FileServer(gemini.Dir("/tmp"))
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func FileServer(fsys FileSystem) Handler {
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return fileServer{fsys}
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}
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type fileServer struct {
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FileSystem
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}
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func (fs fileServer) ServeGemini(w ResponseWriter, r *Request) {
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ServeFile(w, fs, r.URL.Path)
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}
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// ServeFile responds to the request with the contents of the named file
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// or directory.
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//
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// If the provided file or directory name is a relative path, it is interpreted
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// relative to the current directory and may ascend to parent directories. If
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// the provided name is constructed from user input, it should be sanitized
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// before calling ServeFile.
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func ServeFile(w ResponseWriter, fsys FileSystem, name string) {
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f, err := openFile(fsys, name)
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if err != nil {
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w.Status(StatusNotFound)
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return
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}
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// Detect mimetype
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ext := path.Ext(name)
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mimetype := mime.TypeByExtension(ext)
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w.Meta(mimetype)
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// Copy file to response writer
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_, _ = io.Copy(w, f)
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}
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func openFile(fsys FileSystem, name string) (File, error) {
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f, err := fsys.Open(name)
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if err != nil {
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return nil, err
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}
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stat, err := f.Stat()
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if err != nil {
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return nil, err
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}
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if stat.Mode().IsRegular() {
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return f, nil
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}
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if stat.IsDir() {
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// Try opening index.gmi
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f, err := fsys.Open(path.Join(name, "index.gmi"))
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if err != nil {
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return nil, err
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}
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stat, err := f.Stat()
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if err != nil {
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return nil, err
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}
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if stat.Mode().IsRegular() {
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return f, nil
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}
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}
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return nil, os.ErrNotExist
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}
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