// // WRP - Web Rendering Proxy // // Copyright (c) 2013-2018 Antoni Sawicki // Copyright (c) 2019-2020 Google LLC // package main import ( "bytes" "context" "flag" "fmt" "image" "image/gif" "image/png" "log" "math" "math/rand" "net/http" "net/url" "os" "os/signal" "strconv" "strings" "syscall" "time" "github.com/chromedp/cdproto/css" "github.com/chromedp/cdproto/emulation" "github.com/chromedp/cdproto/page" "github.com/chromedp/chromedp" "github.com/ericpauley/go-quantize/quantize" ) var ( version = "4.5" srv http.Server ctx context.Context cancel context.CancelFunc img = make(map[string]bytes.Buffer) ismap = make(map[string]wrpReq) nodel bool deftype string defgeom geom ) type geom struct { w int64 h int64 c int64 } // WRP Request 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 T string // imgtype o http.ResponseWriter r *http.Request } // Parse HTML Form, Process Input Boxes, Etc. func (w *wrpReq) parseForm() { w.r.ParseForm() w.U = w.r.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(w.r.FormValue("w"), 10, 64) w.H, _ = strconv.ParseInt(w.r.FormValue("h"), 10, 64) if w.W < 10 && w.H < 10 { w.W = defgeom.w w.H = defgeom.h } w.S, _ = strconv.ParseFloat(w.r.FormValue("s"), 64) if w.S < 0.1 { w.S = 1.0 } w.C, _ = strconv.ParseInt(w.r.FormValue("c"), 10, 64) if w.C < 2 || w.C > 256 { w.C = defgeom.c } w.K = w.r.FormValue("k") w.F = w.r.FormValue("Fn") w.T = w.r.FormValue("t") if w.T != "gif" && w.T != "png" { w.T = deftype } log.Printf("%s WrpReq from Form: %+v\n", w.r.RemoteAddr, w) } // Display WP UI // TODO: make this in to an external template func (w wrpReq) printPage(bgcolor string) { var s string w.o.Header().Set("Cache-Control", "max-age=0") w.o.Header().Set("Expires", "-1") w.o.Header().Set("Pragma", "no-cache") w.o.Header().Set("Content-Type", "text/html") fmt.Fprintf(w.o, "\n", version) fmt.Fprintf(w.o, "\nWRP %s\n\n", w.U, bgcolor) fmt.Fprintf(w.o, "
\n") fmt.Fprintf(w.o, "", w.U) fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "W \n", w.W) fmt.Fprintf(w.o, "H \n", w.H) fmt.Fprintf(w.o, "S \n") fmt.Fprintf(w.o, "T \n") fmt.Fprintf(w.o, "C \n", w.C) fmt.Fprintf(w.o, "K \n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "\n") fmt.Fprintf(w.o, "

\n") } // Status bar below captured image func (w wrpReq) printFooter(h string, s string) { fmt.Fprintf(w.o, "\n

"+ "Web Rendering Proxy Version %s | Shutdown WRP | "+ "Page Height: %s | Img Size: %s\n\n", w.W, w.H, w.S, w.C, w.T, version, h, s) } // Process HTTP requests to WRP '/' url 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.r = req w.o = out w.parseForm() if len(w.U) > 4 { w.navigate() w.capture() } else { w.printPage("#FFFFFF") w.printFooter("", "") } } // Process HTTP requests to ISMAP '/map/' url 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] w.r = req w.o = out 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.navigate() w.capture() } else { w.printPage("#FFFFFF") w.printFooter("", "") } } // Process HTTP requests for images '/img/' url func imgServer(out http.ResponseWriter, req *http.Request) { log.Printf("%s IMG Request for %s\n", req.RemoteAddr, req.URL.Path) imgbuf, ok := img[req.URL.Path] if !ok || imgbuf.Bytes() == nil { fmt.Fprintf(out, "Unable to find image %s\n", req.URL.Path) log.Printf("%s Unable to find image %s\n", req.RemoteAddr, req.URL.Path) return } if !nodel { defer delete(img, req.URL.Path) } if strings.HasPrefix(req.URL.Path, ".gif") { out.Header().Set("Content-Type", "image/gif") } else if strings.HasPrefix(req.URL.Path, ".png") { out.Header().Set("Content-Type", "image/png") } out.Header().Set("Content-Length", strconv.Itoa(len(imgbuf.Bytes()))) out.Header().Set("Cache-Control", "max-age=0") out.Header().Set("Expires", "-1") out.Header().Set("Pragma", "no-cache") out.Write(imgbuf.Bytes()) out.(http.Flusher).Flush() } // Process HTTP requests for Shutdown via '/shutdown/' url 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) } // Process Keyboard and Mouse events or Navigate to the desired URL. func (w wrpReq) navigate() { var err error // Mouse Click if w.X > 0 && w.Y > 0 { log.Printf("%s Mouse Click %d,%d\n", w.r.RemoteAddr, w.X, w.Y) err = chromedp.Run(ctx, chromedp.MouseClickXY(float64(w.X)/float64(w.S), float64(w.Y)/float64(w.S))) // Buttons } else if len(w.F) > 0 { log.Printf("%s Button %v\n", w.r.RemoteAddr, 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")) } // Keys } else if len(w.K) > 0 { log.Printf("%s Sending Keys: %#v\n", w.r.RemoteAddr, w.K) err = chromedp.Run(ctx, chromedp.KeyEvent(w.K)) // Navigate to URL } else { log.Printf("%s Processing Capture Request for %s\n", w.r.RemoteAddr, w.U) err = chromedp.Run(ctx, chromedp.Navigate(w.U)) } if err != nil { if err.Error() == "context canceled" { log.Printf("%s Contex cancelled, try again", w.r.RemoteAddr) fmt.Fprintf(w.o, "
%s
-- restarting, try again", err) ctx, cancel = chromedp.NewContext(context.Background()) } else { log.Printf("%s %s", w.r.RemoteAddr, err) fmt.Fprintf(w.o, "
%s
", err) } return } } // Capture currently rendered web page to an image and fake ISMAP func (w wrpReq) capture() { var err error var styles []*css.ComputedStyleProperty var r, g, b int var h int64 var pngcap []byte chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.W)/w.S), 10, w.S, false), chromedp.Sleep(time.Second*2), chromedp.Location(&w.U), chromedp.ComputedStyle("body", &styles, chromedp.ByQuery), chromedp.ActionFunc(func(ctx context.Context) error { _, _, s, err := page.GetLayoutMetrics().Do(ctx) if err == nil { h = int64(math.Ceil(s.Height)) } return nil }), ) for _, style := range styles { if style.Name == "background-color" { fmt.Sscanf(style.Value, "rgb(%d,%d,%d)", &r, &g, &b) } } log.Printf("%s Landed on: %s, Height: %v\n", w.r.RemoteAddr, w.U, h) w.printPage(fmt.Sprintf("#%02X%02X%02X", r, g, b)) if w.H == 0 && h > 0 { chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.W)/w.S), h+30, w.S, false)) } else { chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.W)/w.S), int64(float64(w.H)/w.S), w.S, false)) } err = chromedp.Run(ctx, chromedp.CaptureScreenshot(&pngcap)) if err != nil { log.Printf("%s Failed to capture screenshot: %s\n", w.r.RemoteAddr, err) fmt.Fprintf(w.o, "
Unable to capture screenshot:
%s
\n", err) return } seq := rand.Intn(9999) imgpath := fmt.Sprintf("/img/%04d.%s", seq, w.T) mappath := fmt.Sprintf("/map/%04d.map", seq) ismap[mappath] = w var ssize string var sw, sh int if w.T == "gif" { i, err := png.Decode(bytes.NewReader(pngcap)) if err != nil { log.Printf("%s Failed to decode screenshot: %s\n", w.r.RemoteAddr, err) fmt.Fprintf(w.o, "
Unable to decode page screenshot:
%s
\n", err) return } var gifbuf bytes.Buffer err = gif.Encode(&gifbuf, i, &gif.Options{NumColors: int(w.C), Quantizer: quantize.MedianCutQuantizer{}}) if err != nil { log.Printf("%s Failed to encode GIF: %s\n", w.r.RemoteAddr, err) fmt.Fprintf(w.o, "
Unable to encode GIF:
%s
\n", err) return } img[imgpath] = gifbuf ssize = fmt.Sprintf("%.1f MB", float32(len(gifbuf.Bytes()))/1024.0/1024.0) sw = i.Bounds().Max.X sh = i.Bounds().Max.Y log.Printf("%s Encoded GIF image: %s, Size: %s, Colors: %d, %dx%d\n", w.r.RemoteAddr, imgpath, ssize, w.C, sw, sh) } else if w.T == "png" { pngbuf := bytes.NewBuffer(pngcap) img[imgpath] = *pngbuf cfg, _, _ := image.DecodeConfig(pngbuf) ssize = fmt.Sprintf("%.1f MB", float32(len(pngbuf.Bytes()))/1024.0/1024.0) sw = cfg.Width sh = cfg.Height log.Printf("%s Got PNG image: %s, Size: %s, %dx%d\n", w.r.RemoteAddr, imgpath, ssize, sw, sh) } fmt.Fprintf(w.o, "\"Url:", mappath, imgpath, w.U, ssize, sw, sh) w.printFooter(fmt.Sprintf("%d PX", h), ssize) log.Printf("%s Done with caputure for %s\n", w.r.RemoteAddr, w.U) } // Main... func main() { var addr, fgeom string var head, headless bool var debug bool var err error 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 free maps and images after use") flag.StringVar(&deftype, "t", "gif", "Image type: gif|png") flag.StringVar(&fgeom, "g", "1152x600x256", "Geometry: width x height x colors, height can be 0 for unlimited") flag.Parse() if head { headless = false } else { headless = true } n, err := fmt.Sscanf(fgeom, "%dx%dx%d", &defgeom.w, &defgeom.h, &defgeom.c) if err != nil || n != 3 { log.Fatalf("Unable to parse -g geometry flag / %s", err) } 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) } }