feat(web): add file transfer support (#62)

Author: coadler

Diff for: cmd/wasm/main.go

@@ -6,9 +6,12 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
 	"log"
 	"log/slog"
 	"net"
+	"net/http"
+	"strings"
 	"syscall/js"
 	"time"
 
@@ -52,13 +55,8 @@ func main() {
 	<-make(chan struct{}, 0)
 }
 
-func newWush(jsConfig js.Value) map[string]any {
+func newWush(cfg js.Value) map[string]any {
 	ctx := context.Background()
-	var authKey string
-	if jsAuthKey := jsConfig.Get("authKey"); jsAuthKey.Type() == js.TypeString {
-		authKey = jsAuthKey.String()
-	}
-
 	logger := slog.New(slog.NewTextHandler(jsConsoleWriter{}, nil))
 	hlog := func(format string, args ...any) {
 		fmt.Printf(format+"\n", args...)
@@ -68,18 +66,19 @@ func newWush(jsConfig js.Value) map[string]any {
 		panic(err)
 	}
 
-	send := overlay.NewSendOverlay(logger, dm)
-	err = send.Auth.Parse(authKey)
+	ov := overlay.NewWasmOverlay(log.Printf, dm, cfg.Get("onNewPeer"))
+
+	err = ov.PickDERPHome(ctx)
 	if err != nil {
 		panic(err)
 	}
 
-	s, err := tsserver.NewServer(ctx, logger, send, dm)
+	s, err := tsserver.NewServer(ctx, logger, ov, dm)
 	if err != nil {
 		panic(err)
 	}
 
-	go send.ListenOverlayDERP(ctx)
+	go ov.ListenOverlayDERP(ctx)
 	go s.ListenAndServe(ctx)
 	netns.SetDialerOverride(s.Dialer())
 
@@ -94,12 +93,40 @@ func newWush(jsConfig js.Value) map[string]any {
 	}
 	hlog("WireGuard is ready")
 
+	cpListener, err := ts.Listen("tcp", ":4444")
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		err := http.Serve(cpListener, http.HandlerFunc(cpH(
+			cfg.Get("onIncomingFile"),
+			cfg.Get("downloadFile"),
+		)))
+		if err != nil {
+			hlog("File transfer server exited: " + err.Error())
+		}
+	}()
+
 	return map[string]any{
+		"auth_info": js.FuncOf(func(this js.Value, args []js.Value) any {
+			if len(args) != 0 {
+				log.Printf("Usage: auth_info()")
+				return nil
+			}
+
+			return map[string]any{
+				"derp_id":   ov.DerpRegionID,
+				"derp_name": ov.DerpMap.Regions[int(ov.DerpRegionID)].RegionName,
+				"auth_key":  ov.ClientAuth().AuthKey(),
+			}
+		}),
 		"stop": js.FuncOf(func(this js.Value, args []js.Value) any {
 			if len(args) != 0 {
 				log.Printf("Usage: stop()")
 				return nil
 			}
+			cpListener.Close()
 			ts.Close()
 			return nil
 		}),
@@ -127,6 +154,157 @@ func newWush(jsConfig js.Value) map[string]any {
 				}),
 			}
 		}),
+		"connect": js.FuncOf(func(this js.Value, args []js.Value) any {
+			handler := js.FuncOf(func(this js.Value, promiseArgs []js.Value) any {
+				resolve := promiseArgs[0]
+				reject := promiseArgs[1]
+
+				go func() {
+					if len(args) != 1 {
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New("Usage: connect(authKey)")
+						reject.Invoke(errorObject)
+						return
+					}
+
+					var authKey string
+					if args[0].Type() == js.TypeString {
+						authKey = args[0].String()
+					} else {
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New("Usage: connect(authKey)")
+						reject.Invoke(errorObject)
+						return
+					}
+
+					var ca overlay.ClientAuth
+					err := ca.Parse(authKey)
+					if err != nil {
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New(fmt.Errorf("parse authkey: %w", err).Error())
+						reject.Invoke(errorObject)
+						return
+					}
+
+					ctx, cancel := context.WithCancel(context.Background())
+					peer, err := ov.Connect(ctx, ca)
+					if err != nil {
+						cancel()
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New(fmt.Errorf("parse authkey: %w", err).Error())
+						reject.Invoke(errorObject)
+						return
+					}
+
+					resolve.Invoke(map[string]any{
+						"id":   js.ValueOf(peer.ID),
+						"name": js.ValueOf(peer.Name),
+						"ip":   js.ValueOf(peer.IP.String()),
+						"cancel": js.FuncOf(func(this js.Value, args []js.Value) any {
+							cancel()
+							return nil
+						}),
+					})
+				}()
+
+				return nil
+			})
+
+			promiseConstructor := js.Global().Get("Promise")
+			return promiseConstructor.New(handler)
+		}),
+		"transfer": js.FuncOf(func(this js.Value, args []js.Value) any {
+			handler := js.FuncOf(func(this js.Value, promiseArgs []js.Value) any {
+				resolve := promiseArgs[0]
+				reject := promiseArgs[1]
+
+				if len(args) != 5 {
+					errorConstructor := js.Global().Get("Error")
+					errorObject := errorConstructor.New("Usage: transfer(peer, file)")
+					reject.Invoke(errorObject)
+					return nil
+				}
+
+				peer := args[0]
+				ip := peer.Get("ip").String()
+				fileName := args[1].String()
+				sizeBytes := args[2].Int()
+				stream := args[3]
+				streamHelper := args[4]
+
+				pr, pw := io.Pipe()
+
+				goCallback := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+					promiseConstructor := js.Global().Get("Promise")
+					return promiseConstructor.New(js.FuncOf(func(this js.Value, promiseArgs []js.Value) any {
+						resolve := promiseArgs[0]
+						_ = promiseArgs[1]
+						go func() {
+							if len(args) == 0 || args[0].IsNull() || args[0].IsUndefined() {
+								pw.Close()
+								resolve.Invoke()
+								return
+							}
+
+							fmt.Println("in go callback")
+							// Convert the JavaScript Uint8Array to a Go byte slice
+							uint8Array := args[0]
+							fmt.Println("type is", uint8Array.Type().String())
+							length := uint8Array.Get("length").Int()
+							buf := make([]byte, length)
+							js.CopyBytesToGo(buf, uint8Array)
+
+							fmt.Println("sending data to channel")
+							// Send the data to the channel
+							if _, err := pw.Write(buf); err != nil {
+								pw.CloseWithError(err)
+							}
+							fmt.Println("callback finished")
+
+							// Resolve the promise
+							resolve.Invoke()
+						}()
+						return nil
+					}))
+				})
+
+				go func() {
+					defer goCallback.Release()
+
+					streamHelper.Invoke(stream, goCallback)
+
+					hc := ts.HTTPClient()
+					req, err := http.NewRequest(http.MethodPost, fmt.Sprintf("http://%s:4444/%s", ip, fileName), pr)
+					if err != nil {
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New(err.Error())
+						reject.Invoke(errorObject)
+						return
+					}
+					req.ContentLength = int64(sizeBytes)
+
+					res, err := hc.Do(req)
+					if err != nil {
+						errorConstructor := js.Global().Get("Error")
+						errorObject := errorConstructor.New(err.Error())
+						reject.Invoke(errorObject)
+						return
+					}
+					defer res.Body.Close()
+
+					bod := bytes.NewBuffer(nil)
+					_, _ = io.Copy(bod, res.Body)
+
+					fmt.Println(bod.String())
+					resolve.Invoke()
+				}()
+
+				return nil
+			})
+
+			promiseConstructor := js.Global().Get("Promise")
+			return promiseConstructor.New(handler)
+		}),
 	}
 }
 
@@ -306,3 +484,91 @@ func newTSNet(direction string) (*tsnet.Server, error) {
 
 	return srv, nil
 }
+
+func cpH(onIncomingFile js.Value, downloadFile js.Value) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "POST" {
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte("OK"))
+			return
+		}
+
+		fiName := strings.TrimPrefix(r.URL.Path, "/")
+
+		// TODO: impl
+		peer := map[string]any{
+			"id":   js.ValueOf(0),
+			"name": js.ValueOf(""),
+			"ip":   js.ValueOf(""),
+			"cancel": js.FuncOf(func(this js.Value, args []js.Value) any {
+				return nil
+			}),
+		}
+
+		allow := onIncomingFile.Invoke(peer, fiName, r.ContentLength).Bool()
+		if !allow {
+			w.WriteHeader(http.StatusForbidden)
+			w.Write([]byte("File transfer was denied"))
+			r.Body.Close()
+			return
+		}
+
+		underlyingSource := map[string]interface{}{
+			// start method
+			"start": js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+				// The first and only arg is the controller object
+				controller := args[0]
+
+				// Process the stream in yet another background goroutine,
+				// because we can't block on a goroutine invoked by JS in Wasm
+				// that is dealing with HTTP requests
+				go func() {
+					// Close the response body at the end of this method
+					defer r.Body.Close()
+
+					// Read the entire stream and pass it to JavaScript
+					for {
+						// Read up to 16KB at a time
+						buf := make([]byte, 16384)
+						n, err := r.Body.Read(buf)
+						if err != nil && err != io.EOF {
+							// Tell the controller we have an error
+							// We're ignoring "EOF" however, which means the stream was done
+							errorConstructor := js.Global().Get("Error")
+							errorObject := errorConstructor.New(err.Error())
+							controller.Call("error", errorObject)
+							return
+						}
+						if n > 0 {
+							// If we read anything, send it to JavaScript using the "enqueue" method on the controller
+							// We need to convert it to a Uint8Array first
+							arrayConstructor := js.Global().Get("Uint8Array")
+							dataJS := arrayConstructor.New(n)
+							js.CopyBytesToJS(dataJS, buf[0:n])
+							controller.Call("enqueue", dataJS)
+						}
+						if err == io.EOF {
+							// Stream is done, so call the "close" method on the controller
+							controller.Call("close")
+							return
+						}
+					}
+				}()
+
+				return nil
+			}),
+			// cancel method
+			"cancel": js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+				// If the request is canceled, just close the body
+				r.Body.Close()
+
+				return nil
+			}),
+		}
+
+		readableStreamConstructor := js.Global().Get("ReadableStream")
+		readableStream := readableStreamConstructor.New(underlyingSource)
+
+		downloadFile.Invoke(peer, fiName, r.ContentLength, readableStream)
+	}
+}