// // WRP - Web Rendering Proxy // // Copyright (c) 2013-2018 Antoni Sawicki // Copyright (c) 2019 Google LLC // package main import ( "bytes" "context" "flag" "fmt" "image/gif" "image/png" "log" "math/rand" "net/http" "net/url" "os" "os/signal" "strconv" "strings" "syscall" "time" "github.com/chromedp/cdproto/emulation" "github.com/chromedp/chromedp" "github.com/ericpauley/go-quantize/quantize" ) var ( version = "4.4" srv http.Server ctx context.Context cancel context.CancelFunc gifmap = make(map[string]bytes.Buffer) ismap = make(map[string]wrpReq) nodel bool ) type wrpReq struct { U string // url W int64 // width H int64 // height S float64 // scale C int64 // #colors X int64 // mouseX Y int64 // mouseY K string // keys to send F string // Fn buttons } func (w *wrpReq) parseForm(req *http.Request) { req.ParseForm() w.U = req.FormValue("url") if len(w.U) > 1 && !strings.HasPrefix(w.U, "http") { w.U = fmt.Sprintf("http://www.google.com/search?q=%s", url.QueryEscape(w.U)) } w.W, _ = strconv.ParseInt(req.FormValue("w"), 10, 64) if w.W < 10 { w.W = 1152 } w.H, _ = strconv.ParseInt(req.FormValue("h"), 10, 64) if w.H < 10 { w.H = 600 } w.S, _ = strconv.ParseFloat(req.FormValue("s"), 64) if w.S < 0.1 { w.S = 1.0 } w.C, _ = strconv.ParseInt(req.FormValue("c"), 10, 64) if w.C < 2 || w.C > 256 { w.C = 256 } w.K = req.FormValue("k") w.F = req.FormValue("Fn") log.Printf("%s WrpReq from Form: %+v\n", req.RemoteAddr, w) } func (w wrpReq) printPage(out http.ResponseWriter) { out.Header().Set("Cache-Control", "max-age=0") out.Header().Set("Expires", "-1") out.Header().Set("Pragma", "no-cache") out.Header().Set("Content-Type", "text/html") fmt.Fprintf(out, "\n", version) fmt.Fprintf(out, "\nWRP %s\n\n", w.U) fmt.Fprintf(out, "
\n") fmt.Fprintf(out, "", w.U) fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "W \n", w.W) fmt.Fprintf(out, "H \n", w.H) fmt.Fprintf(out, "S \n", w.S) fmt.Fprintf(out, "C \n", w.C) fmt.Fprintf(out, "K \n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "\n") fmt.Fprintf(out, "

\n") } func (w wrpReq) printFooter(out http.ResponseWriter) { fmt.Fprintf(out, "\n

"+ "Web Rendering Proxy Version %s | Shutdown WRP\n\n", w.W, w.H, w.S, w.C, version) } func pageServer(out http.ResponseWriter, req *http.Request) { log.Printf("%s Page Request for %s [%+v]\n", req.RemoteAddr, req.URL.Path, req.URL.RawQuery) var w wrpReq w.parseForm(req) if len(w.U) > 4 { w.capture(req.RemoteAddr, out) } else { w.printPage(out) w.printFooter(out) } } func mapServer(out http.ResponseWriter, req *http.Request) { log.Printf("%s ISMAP Request for %s [%+v]\n", req.RemoteAddr, req.URL.Path, req.URL.RawQuery) w, ok := ismap[req.URL.Path] if !ok { fmt.Fprintf(out, "Unable to find map %s\n", req.URL.Path) log.Printf("Unable to find map %s\n", req.URL.Path) return } if !nodel { defer delete(ismap, req.URL.Path) } n, err := fmt.Sscanf(req.URL.RawQuery, "%d,%d", &w.X, &w.Y) if err != nil || n != 2 { fmt.Fprintf(out, "n=%d, err=%s\n", n, err) log.Printf("%s ISMAP n=%d, err=%s\n", req.RemoteAddr, n, err) return } log.Printf("%s WrpReq from ISMAP: %+v\n", req.RemoteAddr, w) if len(w.U) > 4 { w.capture(req.RemoteAddr, out) } else { w.printPage(out) w.printFooter(out) } } func imgServer(out http.ResponseWriter, req *http.Request) { log.Printf("%s IMG Request for %s\n", req.RemoteAddr, req.URL.Path) gifbuf, ok := gifmap[req.URL.Path] if !ok || gifbuf.Bytes() == nil { fmt.Fprintf(out, "Unable to find image %s\n", req.URL.Path) log.Printf("Unable to find image %s\n", req.URL.Path) return } if !nodel { defer delete(gifmap, req.URL.Path) } out.Header().Set("Content-Type", "image/gif") out.Header().Set("Content-Length", strconv.Itoa(len(gifbuf.Bytes()))) out.Header().Set("Cache-Control", "max-age=0") out.Header().Set("Expires", "-1") out.Header().Set("Pragma", "no-cache") out.Write(gifbuf.Bytes()) out.(http.Flusher).Flush() } func (w wrpReq) capture(c string, out http.ResponseWriter) { var pngbuf []byte var gifbuf bytes.Buffer var err error if w.X > 0 && w.Y > 0 { log.Printf("%s Mouse Click %d,%d\n", c, w.X, w.Y) err = chromedp.Run(ctx, chromedp.MouseClickXY(int64(float64(w.X)/w.S), int64(float64(w.Y)/w.S))) } else if len(w.F) > 0 { log.Printf("%s Button %v\n", c, w.F) switch w.F { case "Bk": err = chromedp.Run(ctx, chromedp.NavigateBack()) case "Bs": err = chromedp.Run(ctx, chromedp.KeyEvent("\b")) case "Rt": err = chromedp.Run(ctx, chromedp.KeyEvent("\r")) case "<": err = chromedp.Run(ctx, chromedp.KeyEvent("\u0302")) case "^": err = chromedp.Run(ctx, chromedp.KeyEvent("\u0304")) case "v": err = chromedp.Run(ctx, chromedp.KeyEvent("\u0301")) case ">": err = chromedp.Run(ctx, chromedp.KeyEvent("\u0303")) } } else if len(w.K) > 0 { log.Printf("%s Sending Keys: %#v\n", c, w.K) err = chromedp.Run(ctx, chromedp.KeyEvent(w.K)) } else { log.Printf("%s Processing Capture Request for %s\n", c, w.U) err = chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.W)/w.S), int64(float64(w.H)/w.S), w.S, false), chromedp.Navigate(w.U), ) } if err != nil { if err.Error() == "context canceled" { log.Printf("%s Contex cancelled, try again", c) fmt.Fprintf(out, "
%s
-- restarting, try again", err) ctx, cancel = chromedp.NewContext(context.Background()) } else { log.Printf("%s %s", c, err) fmt.Fprintf(out, "
%s
", err) } return } chromedp.Run( ctx, chromedp.Sleep(time.Second*2), chromedp.Location(&w.U), ) log.Printf("%s Landed on: %s\n", c, w.U) w.printPage(out) // Process Screenshot Image err = chromedp.Run(ctx, chromedp.CaptureScreenshot(&pngbuf)) if err != nil { log.Printf("%s Failed to capture screenshot: %s\n", c, err) fmt.Fprintf(out, "
Unable to capture screenshot:
%s
\n", err) return } bytes.NewReader(pngbuf).Seek(0, 0) img, err := png.Decode(bytes.NewReader(pngbuf)) if err != nil { log.Printf("%s Failed to decode screenshot: %s\n", c, err) fmt.Fprintf(out, "
Unable to decode page screenshot:
%s
\n", err) return } gifbuf.Reset() err = gif.Encode(&gifbuf, img, &gif.Options{NumColors: int(w.C), Quantizer: quantize.MedianCutQuantizer{}}) if err != nil { log.Printf("%s Failed to encode GIF: %s\n", c, err) fmt.Fprintf(out, "
Unable to encode GIF:
%s
\n", err) return } // Compose map and gif seq := rand.Intn(9999) imgpath := fmt.Sprintf("/img/%04d.gif", seq) mappath := fmt.Sprintf("/map/%04d.map", seq) gifmap[imgpath] = gifbuf ismap[mappath] = w log.Printf("%s Encoded GIF image: %s, Size: %dKB, Colors: %d\n", c, imgpath, len(gifbuf.Bytes())/1024, w.C) fmt.Fprintf(out, "", mappath, imgpath) w.printFooter(out) log.Printf("%s Done with caputure for %s\n", c, w.U) } func haltServer(out http.ResponseWriter, req *http.Request) { log.Printf("%s Shutdown Request for %s\n", req.RemoteAddr, req.URL.Path) out.Header().Set("Cache-Control", "max-age=0") out.Header().Set("Expires", "-1") out.Header().Set("Pragma", "no-cache") out.Header().Set("Content-Type", "text/plain") fmt.Fprintf(out, "Shutting down WRP...\n") out.(http.Flusher).Flush() time.Sleep(time.Second * 2) cancel() srv.Shutdown(context.Background()) os.Exit(1) } func main() { var addr string var head, headless bool var debug bool flag.StringVar(&addr, "l", ":8080", "Listen address:port, default :8080") flag.BoolVar(&head, "h", false, "Headed mode - display browser window") flag.BoolVar(&debug, "d", false, "Debug ChromeDP") flag.BoolVar(&nodel, "n", false, "Do not delete maps and gif images in memory") flag.Parse() if head { headless = false } else { headless = true } opts := append(chromedp.DefaultExecAllocatorOptions[:], chromedp.Flag("headless", headless), chromedp.Flag("hide-scrollbars", false), ) actx, acancel := chromedp.NewExecAllocator(context.Background(), opts...) defer acancel() if debug { ctx, cancel = chromedp.NewContext(actx, chromedp.WithDebugf(log.Printf)) } else { ctx, cancel = chromedp.NewContext(actx) } defer cancel() rand.Seed(time.Now().UnixNano()) c := make(chan os.Signal) signal.Notify(c, os.Interrupt, syscall.SIGTERM) go func() { <-c log.Printf("Interrupt - shutting down.") cancel() srv.Shutdown(context.Background()) os.Exit(1) }() http.HandleFunc("/", pageServer) http.HandleFunc("/map/", mapServer) http.HandleFunc("/img/", imgServer) http.HandleFunc("/shutdown/", haltServer) http.HandleFunc("/favicon.ico", http.NotFound) log.Printf("Web Rendering Proxy Version %s\n", version) log.Printf("Starting WRP http server on %s\n", addr) srv.Addr = addr err := srv.ListenAndServe() if err != nil { log.Fatal(err) } }