// // 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 { url string // url width int64 // width height int64 // height scale float64 // scale colors int64 // #colors mouseX int64 // mouseX mouseY int64 // mouseY keys string // keys to send buttons string // Fn buttons imgType string // imgtype out http.ResponseWriter req *http.Request } // Parse HTML Form, Process Input Boxes, Etc. func (w *wrpReq) parseForm() { w.req.ParseForm() w.url = w.req.FormValue("url") if len(w.url) > 1 && !strings.HasPrefix(w.url, "http") { w.url = fmt.Sprintf("http://www.google.com/search?q=%s", url.QueryEscape(w.url)) } w.width, _ = strconv.ParseInt(w.req.FormValue("w"), 10, 64) w.height, _ = strconv.ParseInt(w.req.FormValue("h"), 10, 64) if w.width < 10 && w.height < 10 { w.width = defgeom.w w.height = defgeom.h } w.scale, _ = strconv.ParseFloat(w.req.FormValue("s"), 64) if w.scale < 0.1 { w.scale = 1.0 } w.colors, _ = strconv.ParseInt(w.req.FormValue("c"), 10, 64) if w.colors < 2 || w.colors > 256 { w.colors = defgeom.c } w.keys = w.req.FormValue("k") w.buttons = w.req.FormValue("Fn") w.imgType = w.req.FormValue("t") if w.imgType != "gif" && w.imgType != "png" { w.imgType = deftype } log.Printf("%s WrpReq from UI Form: %+v\n", w.req.RemoteAddr, w) } // Display WP UI // TODO: make this in to an external template func (w wrpReq) printPage(bgcolor string) { var s string w.out.Header().Set("Cache-Control", "max-age=0") w.out.Header().Set("Expires", "-1") w.out.Header().Set("Pragma", "no-cache") w.out.Header().Set("Content-Type", "text/html") fmt.Fprintf(w.out, "\n", version) fmt.Fprintf(w.out, "\nWRP %s\n\n", w.url, bgcolor) fmt.Fprintf(w.out, "
\n") fmt.Fprintf(w.out, "", w.url) fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "W \n", w.width) fmt.Fprintf(w.out, "H \n", w.height) fmt.Fprintf(w.out, "S \n") fmt.Fprintf(w.out, "T \n") fmt.Fprintf(w.out, "C \n", w.colors) fmt.Fprintf(w.out, "K \n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "\n") fmt.Fprintf(w.out, "

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

"+ ""+ "Web Rendering Proxy Version %s | "+ "Shutdown WRP | "+ "Page Height: %s |"+ "Img Size: %s "+ "\n\n", w.width, w.height, w.scale, w.colors, w.imgType, 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.req = req w.out = out w.parseForm() if len(w.url) > 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.req = req w.out = 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.mouseX, &w.mouseY) 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.url) > 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.mouseX > 0 && w.mouseY > 0 { log.Printf("%s Mouse Click %d,%d\n", w.req.RemoteAddr, w.mouseX, w.mouseY) err = chromedp.Run(ctx, chromedp.MouseClickXY(float64(w.mouseX)/float64(w.scale), float64(w.mouseY)/float64(w.scale))) // Buttons } else if len(w.buttons) > 0 { log.Printf("%s Button %v\n", w.req.RemoteAddr, w.buttons) switch w.buttons { 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.keys) > 0 { log.Printf("%s Sending Keys: %#v\n", w.req.RemoteAddr, w.keys) err = chromedp.Run(ctx, chromedp.KeyEvent(w.keys)) // Navigate to URL } else { log.Printf("%s Processing Capture Request for %s\n", w.req.RemoteAddr, w.url) err = chromedp.Run(ctx, chromedp.Navigate(w.url)) } if err != nil { if err.Error() == "context canceled" { log.Printf("%s Contex cancelled, try again", w.req.RemoteAddr) fmt.Fprintf(w.out, "
%s
-- restarting, try again", err) ctx, cancel = chromedp.NewContext(context.Background()) } else { log.Printf("%s %s", w.req.RemoteAddr, err) fmt.Fprintf(w.out, "
%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.width)/w.scale), 10, w.scale, false), chromedp.Sleep(time.Second*2), chromedp.Location(&w.url), 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.req.RemoteAddr, w.url, h) w.printPage(fmt.Sprintf("#%02X%02X%02X", r, g, b)) if w.height == 0 && h > 0 { chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.width)/w.scale), h+30, w.scale, false)) } else { chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w.width)/w.scale), int64(float64(w.height)/w.scale), w.scale, false)) } // Capture screenshot... err = chromedp.Run(ctx, chromedp.CaptureScreenshot(&pngcap)) if err != nil { if err.Error() == "context canceled" { log.Printf("%s Contex cancelled, try again", w.req.RemoteAddr) fmt.Fprintf(w.out, "
%s
-- restarting, try again", err) ctx, cancel = chromedp.NewContext(context.Background()) } else { log.Printf("%s Failed to capture screenshot: %s\n", w.req.RemoteAddr, err) fmt.Fprintf(w.out, "
Unable to capture screenshot:
%s
\n", err) } return } seq := rand.Intn(9999) imgpath := fmt.Sprintf("/img/%04d.%s", seq, w.imgType) mappath := fmt.Sprintf("/map/%04d.map", seq) ismap[mappath] = w var ssize string var sw, sh int if w.imgType == "gif" { i, err := png.Decode(bytes.NewReader(pngcap)) if err != nil { log.Printf("%s Failed to decode screenshot: %s\n", w.req.RemoteAddr, err) fmt.Fprintf(w.out, "
Unable to decode page screenshot:
%s
\n", err) return } var gifbuf bytes.Buffer err = gif.Encode(&gifbuf, i, &gif.Options{NumColors: int(w.colors), Quantizer: quantize.MedianCutQuantizer{}}) if err != nil { log.Printf("%s Failed to encode GIF: %s\n", w.req.RemoteAddr, err) fmt.Fprintf(w.out, "
Unable to encode GIF:
%s
\n", err) return } img[imgpath] = gifbuf ssize = fmt.Sprintf("%.0f KB", float32(len(gifbuf.Bytes()))/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.req.RemoteAddr, imgpath, ssize, w.colors, sw, sh) } else if w.imgType == "png" { pngbuf := bytes.NewBuffer(pngcap) img[imgpath] = *pngbuf cfg, _, _ := image.DecodeConfig(pngbuf) ssize = fmt.Sprintf("%.0f KB", float32(len(pngbuf.Bytes()))/1024.0) sw = cfg.Width sh = cfg.Height log.Printf("%s Got PNG image: %s, Size: %s, %dx%d\n", w.req.RemoteAddr, imgpath, ssize, sw, sh) } fmt.Fprintf(w.out, "\"Url:", mappath, imgpath, w.url, ssize, sw, sh) w.printFooter(fmt.Sprintf("%d PX", h), ssize) log.Printf("%s Done with caputure for %s\n", w.req.RemoteAddr, w.url) } // 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 } if len(os.Getenv("PORT")) > 0 { addr = ":" + os.Getenv(("PORT")) } 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("Args: %q", os.Args) log.Printf("Default Img Type: %v, Geometry: %+v", deftype, defgeom) log.Printf("Starting WRP http server on %s\n", addr) srv.Addr = addr err = srv.ListenAndServe() if err != nil { log.Fatal(err) } }