debug proxy for tunnel interfaces

Author: dmissmann

ios/debugproxy/binforward.go renamed to ios/debugproxy/usbmuxd/binforward.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"encoding/hex"

ios/debugproxy/debugproxy.go renamed to ios/debugproxy/usbmuxd/debugproxy.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"encoding/json"
@@ -77,8 +77,8 @@ func (d *DebugProxy) retrieveServiceInfoByPort(port uint16) (PhoneServiceInforma
 }
 
 // NewDebugProxy creates a new Default proxy
-func NewDebugProxy() *DebugProxy {
-	return &DebugProxy{mux: sync.Mutex{}, serviceList: []PhoneServiceInformation{}}
+func NewDebugProxy(workdir string) *DebugProxy {
+	return &DebugProxy{mux: sync.Mutex{}, serviceList: []PhoneServiceInformation{}, WorkingDir: workdir}
 }
 
 // Launch moves the original /var/run/usbmuxd to /var/run/usbmuxd.real and starts the server at /var/run/usbmuxd
@@ -104,7 +104,6 @@ func (d *DebugProxy) Launch(device ios.DeviceEntry, binaryMode bool) error {
 		log.WithFields(log.Fields{"error": err, "socket": ios.GetUsbmuxdSocket()}).Error("Unable to move, lacking permissions?")
 		return err
 	}
-	d.setupDirectory()
 	listener, err := net.Listen("unix", ios.ToUnixSocketPath(ios.GetUsbmuxdSocket()))
 	if err != nil {
 		log.Error("Could not listen on usbmuxd socket, do I have access permissions?", err)

ios/debugproxy/decoders.go renamed to ios/debugproxy/usbmuxd/decoders.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"bytes"

ios/debugproxy/dumpingconn.go renamed to ios/debugproxy/usbmuxd/dumpingconn.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"encoding/hex"

ios/debugproxy/lockdownhandler.go renamed to ios/debugproxy/usbmuxd/lockdownhandler.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"bytes"

ios/debugproxy/muxhandler.go renamed to ios/debugproxy/usbmuxd/muxhandler.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"bytes"

ios/debugproxy/socket_mover.go renamed to ios/debugproxy/usbmuxd/socket_mover.go

@@ -1,4 +1,4 @@
-package debugproxy
+package usbmuxd
 
 import (
 	"fmt"

ios/debugproxy/utun/capture.go

@@ -0,0 +1,96 @@
+//go:build darwin
+
+package utun
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/danielpaulus/go-ios/ios"
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	"github.com/google/gopacket/pcap"
+	log "github.com/sirupsen/logrus"
+)
+
+type direction uint8
+
+const (
+	outgoing = iota
+	incoming
+)
+
+type connections map[connectionId]*connection
+
+type connectionId struct {
+	localPort  layers.TCPPort
+	remotePort layers.TCPPort
+}
+
+func Live(ctx context.Context, iface string, provider ios.RsdPortProvider, dumpDir string) error {
+	addr, err := ifaceAddr(iface)
+	if err != nil {
+		return err
+	}
+	log.Infof("Capture traffice for iface %s with address %s", iface, addr)
+	if handle, err := pcap.OpenLive(iface, 64*1024, true, pcap.BlockForever); err != nil {
+		return fmt.Errorf("Live: failed to connect to iface %s. %w", iface, err)
+	} else {
+		packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
+		s := newSession(packetSource.Packets(), addr, provider, dumpDir)
+		s.readPackets(ctx)
+	}
+	return nil
+}
+
+func ifaceAddr(name string) (net.IP, error) {
+	ifaces, err := pcap.FindAllDevs()
+	if err != nil {
+		return nil, err
+	}
+	for _, iface := range ifaces {
+		if iface.Name == name {
+			return iface.Addresses[1].IP, nil
+		}
+	}
+	return nil, fmt.Errorf("ifaceAddr: could not find iface with name %s", name)
+}
+
+func (s *session) connectionIdentifier(ip *layers.IPv6, tcp *layers.TCP) connectionId {
+	if ip.SrcIP.String() == s.localAddr.String() {
+		return connectionId{
+			localPort:  tcp.SrcPort,
+			remotePort: tcp.DstPort,
+		}
+	} else {
+		return connectionId{
+			localPort:  tcp.DstPort,
+			remotePort: tcp.SrcPort,
+		}
+	}
+}
+
+type payloadWriter struct {
+	incoming io.WriteCloser
+	outgoing io.WriteCloser
+}
+
+func (p payloadWriter) Close() error {
+	inErr := p.incoming.Close()
+	outErr := p.outgoing.Close()
+	return errors.Join(inErr, outErr)
+}
+
+func (p payloadWriter) Write(d direction, b []byte) (int, error) {
+	switch d {
+	case outgoing:
+		return p.outgoing.Write(b)
+	case incoming:
+		return p.incoming.Write(b)
+	default:
+		return 0, fmt.Errorf("Write: unknown direction %d", d)
+	}
+}

ios/debugproxy/utun/capture_noop.go

@@ -0,0 +1,14 @@
+//go:build !darwin
+
+package utun
+
+import (
+	"context"
+	"errors"
+
+	"github.com/danielpaulus/go-ios/ios"
+)
+
+func Live(ctx context.Context, iface string, provider ios.RsdPortProvider, dumpDir string) error {
+	return errors.New("capturing traffic on the utun interface is only supported on MacOS")
+}

ios/debugproxy/utun/connection.go

@@ -0,0 +1,157 @@
+//go:build darwin
+
+package utun
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path"
+
+	"github.com/google/gopacket/layers"
+	"github.com/sirupsen/logrus"
+)
+
+type connection struct {
+	id      connectionId
+	w       payloadWriter
+	outPath string
+	inPath  string
+	service string
+}
+
+func newConnection(id connectionId, p string, service string) (*connection, error) {
+	inPath := path.Join(p, "incoming")
+	incoming, err := os.OpenFile(inPath, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return nil, fmt.Errorf("newConnection: could not open file for incoming connection dump: %w", err)
+	}
+	outPath := path.Join(p, "outgoing")
+	outgoing, err := os.OpenFile(outPath, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return nil, fmt.Errorf("newConnection: could not open file for outgoing connection dump: %w", err)
+	}
+	pw := payloadWriter{
+		incoming: incoming,
+		outgoing: outgoing,
+	}
+	return &connection{
+		id:      id,
+		w:       pw,
+		outPath: outPath,
+		inPath:  inPath,
+		service: service,
+	}, nil
+}
+
+func (c connection) handlePacket(tcp *layers.TCP) {
+	if tcp.SYN && tcp.SrcPort == c.id.localPort {
+		logrus.Infof("new connection %s", c.id)
+	}
+	if len(tcp.Payload) > 0 {
+		c.w.Write(c.direction(tcp), tcp.Payload)
+	}
+}
+
+func (c connection) direction(tcp *layers.TCP) direction {
+	if c.id.localPort == tcp.SrcPort {
+		return outgoing
+	} else {
+		return incoming
+	}
+}
+
+func (c connection) Close() error {
+	_ = c.w.Close()
+	logrus.WithField("connection", c.id.String()).WithField("service", c.service).Info("closing connection")
+	err := parseConnectionData(c.outPath, c.inPath)
+	if err != nil {
+		logrus.WithField("connection", c.id.String()).
+			WithField("service", c.service).
+			WithError(err).
+			Warn("failed parsing data")
+	}
+	return nil
+}
+
+func (c connectionId) String() string {
+	return fmt.Sprintf("%d-%d", c.localPort, c.remotePort)
+}
+
+func parseConnectionData(outgoing string, incoming string) error {
+	dir := path.Dir(outgoing)
+
+	outFile, err := os.OpenFile(outgoing, os.O_RDONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+	inFile, err := os.OpenFile(incoming, os.O_RDONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer inFile.Close()
+
+	t := detectType(outFile)
+
+	switch t {
+	case http2:
+		_ = createDecodingFiles(dir, "http.frames", func(outgoing, incoming pair) error {
+			outErr := decodeHttp2FrameHeaders(outgoing.w, outFile, true)
+			inErr := decodeHttp2FrameHeaders(incoming.w, inFile, false)
+			return errors.Join(outErr, inErr)
+		})
+		_, _ = outFile.Seek(0, io.SeekStart)
+		_, _ = inFile.Seek(0, io.SeekStart)
+		return createDecodingFiles(dir, "http.bin", func(outgoing, incoming pair) error {
+			outErr := decodeHttp2(outgoing.w, outFile, true)
+			inErr := decodeHttp2(incoming.w, inFile, false)
+			if err := errors.Join(outErr, inErr); err != nil {
+				//return err
+			}
+			return parseConnectionData(outgoing.p, incoming.p)
+		})
+	case remoteXpc:
+		return createDecodingFiles(dir, "xpc.jsonl", func(outgoing, incoming pair) error {
+			outErr := decodeRemoteXpc(outgoing.w, outFile)
+			inErr := decodeRemoteXpc(incoming.w, inFile)
+			return errors.Join(outErr, inErr)
+		})
+	case remoteDtx:
+		return createDecodingFiles(dir, "dtx", func(outgoing, incoming pair) error {
+			outErr := decodeRemoteDtx(outgoing.w, outFile)
+			inErr := decodeRemoteDtx(incoming.w, inFile)
+			return errors.Join(outErr, inErr)
+		})
+	default:
+		stat, _ := os.Stat(outgoing)
+		if stat.Size() == 0 {
+			return nil
+		}
+		return fmt.Errorf("unknown content type: %s/%s", outgoing, incoming)
+	}
+}
+
+func createDecodingFiles(dir, suffix string, consumer func(outgoing, incoming pair) error) error {
+	outPath := path.Join(dir, fmt.Sprintf("outgoing.%s", suffix))
+	inPath := path.Join(dir, fmt.Sprintf("incoming.%s", suffix))
+
+	outFile, err := os.OpenFile(outPath, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+	inFile, err := os.OpenFile(inPath, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer inFile.Close()
+
+	return consumer(pair{outPath, outFile}, pair{inPath, inFile})
+}
+
+type pair struct {
+	p string
+	w io.Writer
+}