Send termshark's current pcap with magic wormhole

This commit implements a new console command, "wormhole", that allows
you to transfer termshark's open pcap using magic wormhole -
https://github.com/magic-wormhole/magic-wormhole. Magic wormhole is a
secure and convenient way of getting files from one machine to
another. The sender generates a wormhole code e.g.

  $ wormhole send foo
  Sending 1.9 kB file named 'foo'
  Wormhole code is: 9-phonetic-goldfish
  On the other computer, please run:

  wormhole receive 9-phonetic-goldfish

and then the receiver references the code:

  $ wormhole receive 9-phonetic-goldfish
  Receiving file (1.9 kB) into: foo
  ok? (y/N): y
  ...
  Received file written to foo

When you run termshark's wormhole command, termshark generates a
wormhole code and displays it in a dialog. You can then use magic
wormhole locally to transfer the pcap to your desktop. The purpose of
this is to make it easy to get a pcap into Wireshark. Termshark can be
fine for a quick analysis, but Wireshark is much more powerful :-)

To make this process even easier, you can pair this new command with the
tmux-wormhole tmux plugin. You can find it here:
https://github.com/gcla/tmux-wormhole. This can help if your tmux is
local, and within that tmux you are sshed to a remote machine and using
termshark there. As long as the remote machine has internet access, you
should be able to magic-wormhole the pcap. Once you see termshark's
wormhole code on the screen, hit the plugin hotkey - C-b w by default -
and the plugin will detect the code and let you download and open the
pcap. If your desktop association for pcap files is Wireshark, then it
should open in Wireshark. Here's a demo of it in action:

https://drive.google.com/file/d/16qCXyjWS8smzjOeJLGZiplib3frgK4F5/view?usp=sharing

This implementation uses psanford/wormhole-william, a Go implementation
of the magic wormhole protocol.

CHANGELOG.md

@@ -10,6 +10,8 @@
 - The packet structure view now provides a contextual menu with options to
   - apply the structure filter as a custom column
   - prepare or apply the same filter as a display filter
+- A new console-command, "wormhole", allows you to send termshark's current pcap with magic wormhole. Pair
+  with the tmux plugin tmux-wormhole to open the pcap quickly in Wireshark.
 
 ### Changed
 

cmd/termshark/termshark.go

@@ -30,6 +30,7 @@ import (
 	"github.com/gcla/termshark/v2/tty"
 	"github.com/gcla/termshark/v2/ui"
 	"github.com/gcla/termshark/v2/widgets/filter"
+	"github.com/gcla/termshark/v2/widgets/wormhole"
 	"github.com/gdamore/tcell"
 	flags "github.com/jessevdk/go-flags"
 	"github.com/mattn/go-isatty"
@@ -59,6 +60,7 @@ func main() {
 	capinfo.Goroutinewg = &ensureGoroutinesStopWG
 	convs.Goroutinewg = &ensureGoroutinesStopWG
 	ui.Goroutinewg = &ensureGoroutinesStopWG
+	wormhole.Goroutinewg = &ensureGoroutinesStopWG
 
 	res := cmain()
 	ensureGoroutinesStopWG.Wait()
@@ -1072,6 +1074,9 @@ Loop:
 				// will happen next time round because the quitRequested flag is checked.
 				stopLoaders()
 			}
+			if ui.CurrentWormholeWidget != nil {
+				ui.CurrentWormholeWidget.Close()
+			}
 
 		case sig := <-sigChan:
 			if system.IsSigTSTP(sig) {

go.mod

@@ -24,13 +24,13 @@ require (
 	github.com/pelletier/go-toml v1.8.1 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/pkg/term v1.1.0
+	github.com/psanford/wormhole-william v1.0.6-0.20210402190004-049df45b8d5a
 	github.com/rakyll/statik v0.1.7
 	github.com/shibukawa/configdir v0.0.0-20170330084843-e180dbdc8da0
 	github.com/sirupsen/logrus v1.7.0
 	github.com/spf13/afero v1.5.1 // indirect
 	github.com/spf13/cast v1.3.1 // indirect
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
-	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/spf13/viper v1.7.1
 	github.com/stretchr/testify v1.7.0
 	github.com/tevino/abool v1.2.0
@@ -40,7 +40,6 @@ require (
 	gopkg.in/fsnotify/fsnotify.v1 v1.4.7
 	gopkg.in/ini.v1 v1.62.0 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
 

ui/prochandlers.go

@@ -218,6 +218,19 @@ func (t StartUIWhenThereArePackets) OnPsmlHeader(code pcap.HandlerCode, app gowi
 
 //======================================================================
 
+type ClearWormholeState struct{}
+
+var _ pcap.INewSource = ClearWormholeState{}
+
+func (t ClearWormholeState) OnNewSource(code pcap.HandlerCode, app gowid.IApp) {
+	if CurrentWormholeWidget != nil {
+		CurrentWormholeWidget.Close()
+	}
+	CurrentWormholeWidget = nil
+}
+
+//======================================================================
+
 type ClearMarksHandler struct{}
 
 var _ pcap.IClear = checkGlobalJumpAfterPsml{}

ui/ui.go

@@ -603,6 +603,23 @@ func ratio(r float64) gowid.RenderWithRatio {
 	return gowid.RenderWithRatio{R: r}
 }
 
+type RenderRatioUpTo struct {
+	gowid.RenderWithRatio
+	max int
+}
+
+func (r RenderRatioUpTo) String() string {
+	return fmt.Sprintf("upto(%v,%d)", r.RenderWithRatio, r.max)
+}
+
+func (r RenderRatioUpTo) MaxUnits() int {
+	return r.max
+}
+
+func ratioupto(f float64, max int) RenderRatioUpTo {
+	return RenderRatioUpTo{gowid.RenderWithRatio{R: f}, max}
+}
+
 //======================================================================
 
 // run in app goroutine
@@ -1314,6 +1331,11 @@ func lastLineMode(app gowid.IApp) {
 		return nil
 	}))
 
+	MiniBuffer.Register("wormhole", minibufferFn(func(gowid.IApp, ...string) error {
+		openWormhole(app)
+		return nil
+	}))
+
 	MiniBuffer.Register("menu", minibufferFn(func(gowid.IApp, ...string) error {
 		openGeneralMenu(app)
 		return nil
@@ -2670,6 +2692,7 @@ func RequestLoadInterfaces(psrcs []pcap.IPacketSource, captureFilter string, dis
 			ManageStreamCache{},
 			ManageCapinfoCache{},
 			SetStructWidgets{Loader}, // for OnClear
+			ClearWormholeState{},
 			ClearMarksHandler{},
 			CancelledMessage{},
 		},
@@ -2690,6 +2713,7 @@ func RequestLoadPcapWithCheck(pcapf string, displayFilter string, jump termshark
 		ManageCapinfoCache{},
 		SetStructWidgets{Loader}, // for OnClear
 		MakeCheckGlobalJumpAfterPsml(jump),
+		ClearWormholeState{},
 		ClearMarksHandler{},
 		CancelledMessage{},
 	}
@@ -3062,6 +3086,14 @@ func Build() (*gowid.App, error) {
 				reallyClear(app)
 			},
 		},
+		menuutil.SimpleMenuItem{
+			Txt: "Send Pcap",
+			Key: gowid.MakeKey('s'),
+			CB: func(app gowid.IApp, w gowid.IWidget) {
+				multiMenu1Opener.CloseMenu(generalMenu, app)
+				openWormhole(app)
+			},
+		},
 		menuutil.SimpleMenuItem{
 			Txt: "Edit Columns",
 			Key: gowid.MakeKey('e'),

ui/wormhole.go

@@ -0,0 +1,76 @@
+// Copyright 2019-2020 Graham Clark. All rights reserved.  Use of this source
+// code is governed by the MIT license that can be found in the LICENSE
+// file.
+
+// Package ui contains user-interface functions and helpers for termshark.
+package ui
+
+import (
+	"fmt"
+
+	"github.com/gcla/gowid"
+	"github.com/gcla/gowid/widgets/dialog"
+	"github.com/gcla/gowid/widgets/framed"
+	"github.com/gcla/termshark/v2"
+	"github.com/gcla/termshark/v2/widgets/wormhole"
+	log "github.com/sirupsen/logrus"
+)
+
+//======================================================================
+
+var CurrentWormholeWidget *wormhole.Widget
+
+func openWormhole(app gowid.IApp) {
+
+	var numWords int
+	if CurrentWormholeWidget == nil {
+		numWords = termshark.ConfInt("main.wormhole-length", 2)
+	} else {
+		numWords = CurrentWormholeWidget.CodeLength()
+	}
+
+	if CurrentWormholeWidget == nil {
+		var err error
+		CurrentWormholeWidget, err = wormhole.New(Loader.PcapPdml, app, wormhole.Options{
+			ErrorHandler: func(err error, app gowid.IApp) {
+				msg := fmt.Sprintf("Problem sending pcap: %v", err)
+				log.Error(msg)
+				OpenError(msg, app)
+			},
+			CodeLength:          numWords,
+			TransitRelayAddress: termshark.ConfString("main.wormhole-transit-relay", ""),
+			RendezvousURL:       termshark.ConfString("main.wormhole-rendezvous-url", ""),
+		})
+		if err != nil {
+			msg := fmt.Sprintf("%v", err)
+			log.Error(msg)
+			OpenError(msg, app)
+			return
+		}
+	}
+
+	wormholeDialog := dialog.New(
+		framed.NewSpace(
+			CurrentWormholeWidget,
+		),
+		dialog.Options{
+			Buttons:         []dialog.Button{dialog.CloseD},
+			NoShadow:        true,
+			BackgroundStyle: gowid.MakePaletteRef("dialog"),
+			BorderStyle:     gowid.MakePaletteRef("dialog"),
+			ButtonStyle:     gowid.MakePaletteRef("dialog-button"),
+		},
+	)
+
+	// space for the frame; then XXX-word1-word2-... - max length of word in
+	// pgp word list is 11. Yuck.
+	maxl := (2 * 3) + len(" - cancelled!") + wormhole.UpperBoundOnLength(numWords)
+
+	wormholeDialog.Open(appView, ratioupto(0.8, maxl), app)
+}
+
+//======================================================================
+// Local Variables:
+// mode: Go
+// fill-column: 110
+// End: