package gopherproxy import ( "fmt" "html/template" "io" "io/ioutil" "log" "net/http" "net/url" "strings" "github.com/prologic/go-gopher" ) type tplRow struct { Link template.URL Type string Text string } // Handler is an aliased type for the standard HTTP handler functions type Handler func(w http.ResponseWriter, req *http.Request) func renderDirectory(w http.ResponseWriter, tpl *template.Template, hostport string, d gopher.Directory) error { out := make([]tplRow, len(d)) for i, x := range d { tr := tplRow{ Text: x.Description, Type: x.Type.String(), } if x.Type == gopher.INFO { out[i] = tr continue } if strings.HasPrefix(x.Selector, "URL:") { tr.Link = template.URL(x.Selector[4:]) } else { var hostport string if x.Port == 70 { hostport = x.Host } else { hostport = fmt.Sprintf("%s:%d", x.Host, x.Port) } path := url.QueryEscape(x.Selector) path = strings.Replace(path, "%2F", "/", -1) tr.Link = template.URL( fmt.Sprintf( "/%s/%s%s", hostport, string(byte(x.Type)), path, ), ) } out[i] = tr } return tpl.Execute(w, struct { Title string Lines []tplRow }{hostport, out}) } // MakeGopherProxyHandler returns a Handler that proxies requests // to the specified Gopher server as denoated by the first argument // to the request path and renders the content using the provided template. func MakeGopherProxyHandler(tpl *template.Template, uri string) Handler { return func(w http.ResponseWriter, req *http.Request) { parts := strings.Split(strings.TrimPrefix(req.URL.Path, "/"), "/") hostport := parts[0] path := strings.Join(parts[1:], "/") if len(hostport) == 0 { http.Redirect(w, req, "/"+uri, http.StatusFound) return } uri, err := url.QueryUnescape(path) if err != nil { io.WriteString(w, fmt.Sprintf("Error:
%s
", err)) return } res, err := gopher.Get( fmt.Sprintf( "gopher://%s/%s", hostport, uri, ), ) if err != nil { io.WriteString(w, fmt.Sprintf("Error:
%s
", err)) return } if res.Body != nil { io.Copy(w, res.Body) } else { if err := renderDirectory(w, tpl, hostport, res.Dir); err != nil { io.WriteString(w, fmt.Sprintf("Error:
%s
", err)) return } } } } // ListenAndServe creates a listening HTTP server bound to // the interface specified by bind and sets up a Gopher to HTTP // proxy proxying requests as requested and by default will prozy // to a Gopher server address specified by uri if no servers is // specified by the request. func ListenAndServe(bind, uri string) error { var tpl *template.Template tpldata, err := ioutil.ReadFile(".template") if err == nil { tpltext = string(tpldata) } tpl, err = template.New("gophermenu").Parse(tpltext) if err != nil { log.Fatal(err) } http.HandleFunc("/", MakeGopherProxyHandler(tpl, uri)) return http.ListenAndServe(bind, nil) }