156 lines
3.2 KiB
Go
156 lines
3.2 KiB
Go
package gemini
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import (
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"fmt"
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"io"
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"io/fs"
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"mime"
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"net/url"
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"path"
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"sort"
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"strings"
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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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// 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 os.DirFS:
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//
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// gemini.FileServer(os.DirFS("/tmp"))
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func FileServer(fsys fs.FS) Handler {
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return fileServer{fsys}
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}
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type fileServer struct {
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fs.FS
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}
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func (fs fileServer) ServeGemini(w ResponseWriter, r *Request) {
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serveFile(w, r, fs, path.Clean(r.URL.Path), true)
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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, r *Request, fsys fs.FS, name string) {
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serveFile(w, r, fsys, name, false)
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}
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func serveFile(w ResponseWriter, r *Request, fsys fs.FS, name string, redirect bool) {
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const indexPage = "/index.gmi"
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// Redirect .../index.gmi to .../
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if strings.HasSuffix(r.URL.Path, indexPage) {
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w.Header(StatusPermanentRedirect, "./")
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return
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}
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if name == "/" {
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name = "."
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} else {
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name = strings.Trim(name, "/")
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}
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f, err := fsys.Open(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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defer f.Close()
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stat, err := f.Stat()
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if err != nil {
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w.Status(StatusTemporaryFailure)
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return
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}
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// Redirect to canonical path
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if redirect {
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url := r.URL.Path
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if stat.IsDir() {
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// Add trailing slash
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if url[len(url)-1] != '/' {
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w.Header(StatusPermanentRedirect, path.Base(url)+"/")
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return
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}
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} else {
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// Remove trailing slash
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if name[len(name)-1] == '/' {
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w.Header(StatusPermanentRedirect, "../"+path.Base(url))
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return
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}
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}
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}
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if stat.IsDir() {
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// Redirect if the directory name doesn't end in a slash
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url := r.URL.Path
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if url[len(url)-1] != '/' {
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w.Header(StatusRedirect, path.Base(url)+"/")
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return
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}
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// Use contents of index.gmi if present
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index, err := fsys.Open(path.Join(name, indexPage))
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if err == nil {
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defer index.Close()
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istat, err := index.Stat()
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if err == nil {
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f = index
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stat = istat
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}
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}
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}
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if stat.IsDir() {
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// Failed to find index file
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dirList(w, f)
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return
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}
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// Detect mimetype from file extension
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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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io.Copy(w, f)
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}
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func dirList(w ResponseWriter, f fs.File) {
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var entries []fs.DirEntry
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var err error
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d, ok := f.(fs.ReadDirFile)
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if ok {
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entries, err = d.ReadDir(-1)
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}
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if !ok || err != nil {
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w.Header(StatusTemporaryFailure, "Error reading directory")
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return
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}
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sort.Slice(entries, func(i, j int) bool {
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return entries[i].Name() < entries[j].Name()
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})
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for _, entry := range entries {
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name := entry.Name()
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if entry.IsDir() {
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name += "/"
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}
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link := LineLink{
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Name: name,
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URL: (&url.URL{Path: name}).EscapedPath(),
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}
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fmt.Fprintln(w, link.String())
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}
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}
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