adding tcp traceroute capabilities to Feature/tlsmiddleboxprobe

internal/experiment/tlsmiddlebox/tcp_traceroute_probe.go

@@ -0,0 +1,260 @@
+package tlsmiddlebox
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net"
+	"strconv"
+	"sync"
+	"time"
+	"unsafe"
+
+	"github.com/ooni/probe-cli/v3/internal/logx"
+	"github.com/ooni/probe-cli/v3/internal/model"
+	"golang.org/x/sys/unix"
+)
+
+func parseQuotedPacket(buf []byte) (*model.ArchivalICMPQuotation, error) {
+	if len(buf) < 8 {
+		return nil, fmt.Errorf("tcp quote too short")
+	}
+
+	quotedPacket := &model.ArchivalICMPQuotation{
+		Protocol:  6,
+		SrcPort:   int(binary.BigEndian.Uint16(buf[0:2])),
+		DstPort:   int(binary.BigEndian.Uint16(buf[2:4])),
+		TCPSeqNum: binary.BigEndian.Uint32(buf[4:8]),
+	}
+
+	return quotedPacket, nil
+}
+
+func probeTCP(address string, ttl int, timeoutMS int, wg *sync.WaitGroup, logger model.Logger, index int64) (*ICMPIteration, error) {
+	defer wg.Done()
+	host, portString, err := net.SplitHostPort(address)
+
+	if err != nil {
+		return nil, err
+	}
+
+	port, err := strconv.Atoi(portString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	fd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, unix.IPPROTO_TCP)
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer unix.Close(fd)
+
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_IP, unix.IP_RECVERR, 1); err != nil {
+		return nil, err
+	}
+
+	if err := unix.SetNonblock(fd, true); err != nil {
+		return nil, err
+	}
+
+	if err := unix.SetsockoptInt(fd, unix.IPPROTO_IP, unix.IP_TTL, ttl); err != nil {
+		return nil, err
+	}
+
+	timestampFlags := unix.SOF_TIMESTAMPING_TX_SOFTWARE |
+		unix.SOF_TIMESTAMPING_RX_SOFTWARE |
+		unix.SOF_TIMESTAMPING_SOFTWARE
+
+	if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_TIMESTAMPING, timestampFlags); err != nil {
+		return nil, err
+	}
+
+	ip := net.ParseIP(host).To4()
+	if ip == nil {
+		return nil, fmt.Errorf("invalid IPv4 address")
+	}
+
+	var addr [4]byte
+	copy(addr[:], ip)
+
+	sa := &unix.SockaddrInet4{
+		Port: port,
+		Addr: addr,
+	}
+
+	var txTime *time.Time
+
+	txTimeVal := time.Now()
+	txTime = &txTimeVal
+
+	err = unix.Connect(fd, sa)
+	if err != nil && err != unix.EINPROGRESS {
+		return nil, err
+	}
+
+	pfds := []unix.PollFd{
+		{
+			Fd:     int32(fd),
+			Events: unix.POLLOUT | unix.POLLERR,
+		},
+	}
+
+	n, err := unix.Poll(pfds, timeoutMS)
+	if err != nil {
+		return nil, err
+	}
+
+	if n == 0 {
+		ol := logx.NewOperationLogger(logger, "Traceroute #%d TTL %d %s TIMEOUT", index, ttl, address)
+		ol.Stop(nil)
+		ii_timeout := &ICMPIteration{
+			TTL: ttl,
+			ICMPError: &model.ArchivalICMPErrorMessage{
+				Timeout: "yes",
+			},
+		}
+		return ii_timeout, nil
+	}
+
+	if pfds[0].Revents&unix.POLLERR != 0 {
+
+		buf := make([]byte, 64)
+		oob := make([]byte, 512)
+
+		var data []byte
+		var rxTime *time.Time
+		var eeType byte
+		var eeCode byte
+		var ip net.IP
+		var quotedPacket *model.ArchivalICMPQuotation
+
+		for {
+			n, oobn, _, _, err := unix.Recvmsg(fd, buf, oob, unix.MSG_ERRQUEUE)
+
+			if err == unix.EAGAIN {
+				break
+			}
+
+			if err != nil {
+				return nil, err
+			}
+
+			quoted := buf[:n]
+
+			quotedPacket, err = parseQuotedPacket(quoted)
+
+			if err != nil {
+				fmt.Println("quote parse failed:", err)
+				return nil, err
+			}
+
+			cms, err := unix.ParseSocketControlMessage(oob[:oobn])
+			if err != nil {
+				return nil, err
+			}
+
+			for _, cm := range cms {
+
+				fmt.Printf("n=%d\n", n)
+				fmt.Printf("buf=%x\n", buf[:n])
+
+				switch {
+				case cm.Header.Level == unix.SOL_SOCKET &&
+					cm.Header.Type == unix.SO_TIMESTAMPING:
+					var ts [3]unix.Timespec
+					if len(cm.Data) >= int(unsafe.Sizeof([3]unix.Timespec{})) {
+						ts = *(*[3]unix.Timespec)(unsafe.Pointer(&cm.Data[0]))
+					}
+
+					if ts[0].Sec != 0 {
+						t := time.Unix(ts[0].Sec, ts[0].Nsec)
+						rxTime = &t
+					}
+
+				case cm.Header.Level == unix.IPPROTO_IP &&
+					cm.Header.Type == unix.IP_RECVERR:
+					data = cm.Data
+
+					if len(data) < 16 {
+						continue
+					}
+
+					eeType = data[5]
+					eeCode = data[6]
+
+					if len(data) >= 24 {
+						family := binary.LittleEndian.Uint16(data[16:18])
+
+						if family == unix.AF_INET {
+							ip = net.IP(data[20:24])
+						}
+					}
+
+				}
+			}
+
+		}
+
+		var t0, t float64
+
+		if txTime != nil {
+			t0 = float64(txTime.UnixMilli())
+		}
+
+		if rxTime != nil {
+			t = float64(rxTime.UnixMilli())
+		}
+
+		ii := &ICMPIteration{
+			TTL: ttl,
+			ICMPError: &model.ArchivalICMPErrorMessage{
+				Timeout: "no",
+				SrcIP:   ip.String(),
+				Type:    int(eeType),
+				Code:    int(eeCode),
+				T0:      t0,
+				T:       t,
+			},
+		}
+		if quotedPacket != nil && err == nil {
+			ii.ICMPError.Quote = *quotedPacket
+		}
+
+		ol := logx.NewOperationLogger(logger, "Traceroute #%d TTL %d %s Router %s", index, ttl, address, ip.String())
+		ol.Stop(err)
+		return ii, nil
+	}
+
+	if pfds[0].Revents&unix.POLLOUT != 0 {
+		soerr, err := unix.GetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_ERROR)
+		if err != nil {
+			return nil, err
+		}
+
+		if soerr == 0 {
+			ol := logx.NewOperationLogger(logger, "Traceroute #%d TTL %d %s CONNECTED", index, ttl, address)
+			ol.Stop(nil)
+			ii_connected := &ICMPIteration{
+				TTL: ttl,
+				ICMPError: &model.ArchivalICMPErrorMessage{
+					Connected: "yes",
+				},
+			}
+			return ii_connected, nil
+		} else {
+			ol := logx.NewOperationLogger(logger, "Traceroute #%d TTL %d %s SO_ERROR %v", index, ttl, address, unix.Errno(soerr))
+			ol.Stop(nil)
+			ii_error := &ICMPIteration{
+				TTL: ttl,
+				ICMPError: &model.ArchivalICMPErrorMessage{
+					Error: unix.Errno(soerr).Error(),
+				},
+			}
+			return ii_error, nil
+		}
+	}
+
+	return nil, nil
+}

internal/experiment/tlsmiddlebox/tcp_traceroute_probe_test.go

@@ -0,0 +1,94 @@
+package tlsmiddlebox
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestParseQuotedPacket(t *testing.T) {
+	t.Run("buffer too short", func(t *testing.T) {
+		buf := []byte("Hello")
+		quotedPacket, err := parseQuotedPacket(buf)
+		if quotedPacket == nil && (err == nil || err.Error() != "tcp quote too short") {
+			t.Fatal("failed to error due to quote being too short")
+		}
+	})
+
+	t.Run("success case", func(t *testing.T) {
+		buf := []byte{0xed, 0x6e, 0x01, 0xbb, 0x16, 0xed, 0xf5, 0x4c}
+		quotedPacket, err := parseQuotedPacket(buf)
+
+		if err != nil {
+			t.Fatal("unexpected error:", err)
+		}
+
+		if quotedPacket == nil {
+			t.Fatal("expected *model.ArchivalICMPQuotation, got nil")
+		}
+
+		if quotedPacket.Protocol != 6 {
+			t.Fatalf("expected protocol 6, got %d", quotedPacket.Protocol)
+		}
+
+		if quotedPacket.SrcPort != 60782 {
+			t.Fatalf("expected source port 60782, got %d", quotedPacket.SrcPort)
+		}
+
+		if quotedPacket.DstPort != 443 {
+			t.Fatalf("expected destination port 443, got %d", quotedPacket.DstPort)
+		}
+
+		if quotedPacket.TCPSeqNum != 384693580 {
+			t.Fatalf("expected TCP seq num 384693580, got %d", quotedPacket.TCPSeqNum)
+		}
+	})
+}
+
+func TestProbeTCP(t *testing.T) {
+	wg := new(sync.WaitGroup)
+	ttl := 2
+	index := int64(1)
+
+	t.Run("invalid address and port format", func(t *testing.T) {
+		wg.Add(1)
+		address := "1.2.3.4"
+		ii, err := probeTCP(address, ttl, 3000, wg, model.DiscardLogger, index)
+		if ii != nil {
+			t.Fatalf("expected nil, got %T", ii)
+		}
+
+		if err.Error() != "address 1.2.3.4: missing port in address" {
+			t.Fatalf("expected 'address 1.2.3.4: missing port in address', got %s", err.Error())
+		}
+	})
+
+	t.Run("invalid IPv4 address", func(t *testing.T) {
+		wg.Add(1)
+		address := "298.125.34.4:443"
+		ii, err := probeTCP(address, ttl, 3000, wg, model.DiscardLogger, index)
+		if ii != nil {
+			t.Fatalf("expected nil, got %T", ii)
+		}
+
+		if err.Error() != "invalid IPv4 address" {
+			t.Fatalf("expected 'invalid IPv4 address', got %s", err.Error())
+		}
+
+	})
+
+	t.Run("invalid port number", func(t *testing.T) {
+		wg.Add(1)
+		address := "298.125.34.4:spot"
+		ii, err := probeTCP(address, ttl, 3000, wg, model.DiscardLogger, index)
+		if ii != nil {
+			t.Fatalf("expected nil, got %T", ii)
+		}
+
+		if err.Error() != "strconv.Atoi: parsing \"spot\": invalid syntax" {
+			t.Fatalf("expected 'strconv.Atoi: parsing \"spot\": invalid syntax', got %s", err.Error())
+		}
+	})
+
+}