// // WRP - Web Rendering Proxy // // Copyright (c) 2013-2018 Antoni Sawicki // Copyright (c) 2019 Google LLC // package main import ( "bytes" "context" "flag" "fmt" _ "image" "image/gif" "image/png" "log" "math/rand" "net/http" "net/url" "strconv" "strings" "time" "github.com/chromedp/cdproto/emulation" "github.com/chromedp/cdproto/runtime" "github.com/chromedp/cdproto/cdp" "github.com/chromedp/cdproto/dom" "github.com/chromedp/chromedp" ) // Ismap for server side processing type Ismap struct { xmin int64 ymin int64 xmax int64 ymax int64 url string } var ( version = "3.0" ctx context.Context cancel context.CancelFunc gifmap = make(map[string]bytes.Buffer) ismap = make(map[string][]Ismap) ) func pageServer(out http.ResponseWriter, req *http.Request) { req.ParseForm() u := req.FormValue("url") var istr string var ion string var i bool if req.FormValue("i") == "on" { istr = "CHECKED" i = true ion = "&i=on" } else { istr = "" i = false } p, _ := strconv.ParseInt(req.FormValue("p"), 10, 64) if req.FormValue("pg") == "Dn" { p++ } else if req.FormValue("pg") == "Up" { p-- } else { p = 0 } w, _ := strconv.ParseInt(req.FormValue("w"), 10, 64) if w < 10 { w = 1024 } h, _ := strconv.ParseInt(req.FormValue("h"), 10, 64) if h < 10 { h = 768 } s, _ := strconv.ParseFloat(req.FormValue("s"), 64) if s < 0.1 { s = 1.0 } c, _ := strconv.ParseInt(req.FormValue("c"), 10, 64) if c < 2 || c > 256 { c = 256 } log.Printf("%s Page Reqest for url=\"%s\" [%s]\n", req.RemoteAddr, u, req.URL.Path) out.Header().Set("Content-Type", "text/html") fmt.Fprintf(out, "\n", version) fmt.Fprintf(out, "\nWRP %s\n\n", u) fmt.Fprintf(out, "
", u) fmt.Fprintf(out, " \n") fmt.Fprintf(out, " \n") fmt.Fprintf(out, " \n", p) fmt.Fprintf(out, " \n") fmt.Fprintf(out, "I \n", istr) fmt.Fprintf(out, "W \n", w) fmt.Fprintf(out, "H \n", h) fmt.Fprintf(out, "S \n", s) fmt.Fprintf(out, "C \n", c) fmt.Fprintf(out, "

\n") if len(u) > 1 { if strings.HasPrefix(u, "http") { capture(u, w, h, s, int(c), p, i, req.RemoteAddr, out) } else { capture(fmt.Sprintf("http://www.google.com/search?q=%s", url.QueryEscape(u)), w, h, s, int(c), p, i, req.RemoteAddr, out) } } else { fmt.Fprintf(out, "No URL or search query specified") } fmt.Fprintf(out, "\n

Web Rendering Proxy Version %s\n\n", w, h, s, c, ion, version) } 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 } defer delete(gifmap, req.URL.Path) out.Header().Set("Content-Type", "image/gif") out.Header().Set("Content-Length", strconv.Itoa(len(gifbuf.Bytes()))) out.Write(gifbuf.Bytes()) out.(http.Flusher).Flush() } 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) var loc string var x, y int64 n, err := fmt.Sscanf(req.URL.RawQuery, "%d,%d", &x, &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 } is, ok := ismap[req.URL.Path] if !ok || is == nil { fmt.Fprintf(out, "Unable to find map %s\n", req.URL.Path) log.Printf("Unable to find map %s\n", req.URL.Path) return } defer delete(ismap, req.URL.Path) for _, i := range is { if x >= i.xmin && x <= i.xmax && y >= i.ymin && y <= i.ymax { loc = i.url } } if len(loc) < 1 { loc = is[0].url } log.Printf("%s ISMAP Redirect to: http://%s%s\n", req.RemoteAddr, req.Context().Value(http.LocalAddrContextKey), loc) http.Redirect(out, req, fmt.Sprintf("http://%s%s", req.Context().Value(http.LocalAddrContextKey), loc), 301) } func capture(gourl string, w int64, h int64, s float64, co int, p int64, i bool, c string, out http.ResponseWriter) { var nodes []*cdp.Node ctxx := chromedp.FromContext(ctx) var pngbuf []byte var gifbuf bytes.Buffer var loc string var res *runtime.RemoteObject is := make([]Ismap, 0) var ion string log.Printf("%s Processing Caputure Request for %s\n", c, gourl) // Run ChromeDP Magic err := chromedp.Run(ctx, emulation.SetDeviceMetricsOverride(int64(float64(w)/s), int64(float64(h)/s), s, false), chromedp.Navigate(gourl), chromedp.Evaluate(fmt.Sprintf("window.scrollTo(0, %d);", p*int64(float64(h)*float64(0.9))), &res), chromedp.Sleep(time.Second*1), chromedp.CaptureScreenshot(&pngbuf), chromedp.Location(&loc), chromedp.Nodes("a", &nodes, chromedp.ByQueryAll)) if err != nil { log.Printf("%s %s", c, err) fmt.Fprintf(out, "
%s
", err) return } log.Printf("%s Landed on: %s, Nodes: %d\n", c, loc, len(nodes)) // Process Screenshot Image 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: co}) 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 } seq := rand.Intn(9999) imgpath := fmt.Sprintf("/img/%04d.gif", seq) mappath := fmt.Sprintf("/map/%04d.map", seq) log.Printf("%s Encoded GIF image: %s, Size: %dKB\n", c, imgpath, len(gifbuf.Bytes())/1024) gifmap[imgpath] = gifbuf // Process Nodes base, _ := url.Parse(loc) if i { fmt.Fprintf(out, "\"wrp\"", mappath, imgpath) is = append(is, Ismap{xmin: -1, xmax: -1, ymin: -1, ymax: -1, url: fmt.Sprintf("/?url=%s&w=%d&h=%d&s=%1.2f&c=%d&i=on", loc, w, h, s, co)}) ion = "&i=on" } else { fmt.Fprintf(out, "\"wrp\"\n\n", imgpath) } for _, n := range nodes { b, err := dom.GetBoxModel().WithNodeID(n.NodeID).Do(cdp.WithExecutor(ctx, ctxx.Target)) if err != nil { continue } tgt, err := base.Parse(n.AttributeValue("href")) if err != nil { continue } target := fmt.Sprintf("/?url=%s&w=%d&h=%d&s=%1.2f&c=%d%s", tgt, w, h, s, co, ion) // no page# here if len(b.Content) > 6 && len(target) > 7 { if i { is = append(is, Ismap{ xmin: int64(b.Content[0] * s), ymin: int64(b.Content[1] * s), xmax: int64(b.Content[4] * s), ymax: int64(b.Content[5] * s), url: target}) } else { fmt.Fprintf(out, "\"%s\"\n", b.Content[0]*s, b.Content[1]*s, b.Content[4]*s, b.Content[5]*s, n.AttributeValue("href"), n.AttributeValue("href"), target) } } } if i { log.Printf("%s Encoded ISMAP %s\n", c, mappath) } else { fmt.Fprintf(out, "\n") } out.(http.Flusher).Flush() log.Printf("%s Done with caputure for %s\n", c, gourl) ismap[mappath] = is } 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.Parse() if head { headless = false } else { headless = true } opts := append(chromedp.DefaultExecAllocatorOptions[:], chromedp.Flag("headless", headless), ) actx, cancel := chromedp.NewExecAllocator(context.Background(), opts...) defer cancel() if debug { ctx, cancel = chromedp.NewContext(actx, chromedp.WithDebugf(log.Printf)) } else { ctx, cancel = chromedp.NewContext(actx) } defer cancel() rand.Seed(time.Now().UnixNano()) http.HandleFunc("/", pageServer) http.HandleFunc("/img/", imgServer) http.HandleFunc("/map/", mapServer) 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) http.ListenAndServe(addr, nil) }