Fix run with progress and add new Run function

examples/basic_scan_streamer_interface/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"strings"
+
+	"github.com/Ullaakut/nmap/v2"
+)
+
+// CustomType is your custom type in code.
+// You just have to make it a Streamer.
+type CustomType struct {
+	nmap.Streamer
+	File string
+}
+
+// Write is a function that handles the normal nmap stdout
+func (c *CustomType) Write(d []byte) (int, error) {
+	var err error
+	lines := string(d)
+
+	if strings.Contains(lines, "Stats: ") {
+		fmt.Print(lines)
+	}
+	return len(d), err
+}
+
+// Bytes returns scan result bytes
+func (c *CustomType) Bytes() []byte {
+	data, err := ioutil.ReadFile(c.File)
+	if err != nil {
+		data = append(data, "\ncould not read File"...)
+	}
+	return data
+}
+
+func main() {
+	cType := &CustomType{
+		File: "/tmp/output.xml",
+	}
+	scanner, err := nmap.NewScanner(
+		nmap.WithTargets("localhost"),
+		nmap.WithPorts("1-4000"),
+		nmap.WithServiceInfo(),
+		nmap.WithVerbosity(3),
+	)
+	if err != nil {
+		log.Fatalf("unable to create nmap scanner: %v", err)
+	}
+
+	warnings, err := scanner.RunWithStreamer(cType, cType.File)
+	if err != nil {
+		log.Fatalf("unable to run nmap scan: %v", err)
+	}
+
+	fmt.Printf("Nmap warnings: %v\n", warnings)
+
+	result, err := nmap.Parse(cType.Bytes())
+	if err != nil {
+		log.Fatalf("unable to parse nmap output: %v", err)
+	}
+
+	fmt.Printf("Nmap done: %d hosts up scanned in %.2f seconds\n", len(result.Hosts), result.Stats.Finished.Elapsed)
+}

go.mod

@@ -2,4 +2,8 @@ module github.com/Ullaakut/nmap/v2
 
 go 1.15
 
-require github.com/stretchr/testify v1.6.1
+require (
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.6.1
+	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a
+)

go.sum

@@ -1,10 +1,14 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a h1:DcqTD9SDLc+1P/r1EmRBwnVsrOwW+kk2vWf9n+1sGhs=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

nmap.go

@@ -7,6 +7,9 @@ import (
 	"context"
 	"encoding/xml"
 	"fmt"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
+	"io"
 	"os/exec"
 	"strings"
 	"time"
@@ -17,6 +20,12 @@ type ScanRunner interface {
 	Run() (result *Run, warnings []string, err error)
 }
 
+// Streamer will be used to constantly stream the stdout
+type Streamer interface {
+	Write(d []byte) (int, error)
+	Bytes() []byte
+}
+
 // Scanner represents an Nmap scanner.
 type Scanner struct {
 	cmd *exec.Cmd
@@ -210,14 +219,15 @@ func (s *Scanner) RunWithProgress(liveProgress chan<- float32) (result *Run, war
 	// Wait for nmap process or timeout
 	select {
 	case <-s.ctx.Done():
+		// Trigger progress function exit
+		close(doneProgress)
 
 		// Context was done before the scan was finished.
 		// The process is killed and a timeout error is returned.
 		_ = cmd.Process.Kill()
 
 		return nil, warnings, ErrScanTimeout
 	case <-done:
-
 		// Trigger progress function exit
 		close(doneProgress)
 
@@ -269,6 +279,72 @@ func (s *Scanner) RunWithProgress(liveProgress chan<- float32) (result *Run, war
 	}
 }
 
+// RunWithStreamer runs nmap synchronously. The xml output will be written directly to a file.
+// It uses a streamer interface to constantly stream the stdout.
+func (s *Scanner) RunWithStreamer(stream Streamer, file string) (warnings []string, err error) {
+	// Enable XML output
+	s.args = append(s.args, "-oX")
+
+	// Get XML output in stdout instead of writing it in a file
+	s.args = append(s.args, file)
+
+	// Enable progress output every second
+	s.args = append(s.args, "--stats-every", "5s")
+
+	// Prepare nmap process
+	cmd := exec.CommandContext(s.ctx, s.binaryPath, s.args...)
+
+	// Write stderr to buffer
+	stderrBuf := bytes.Buffer{}
+	cmd.Stderr = &stderrBuf
+
+	// Connect to the StdoutPipe
+	stdoutIn, err := cmd.StdoutPipe()
+	if err != nil {
+		return warnings, errors.WithMessage(err, "connect to StdoutPipe failed")
+	}
+	stdout := stream
+
+	// Run nmap process
+	if err := cmd.Start(); err != nil {
+		return warnings, errors.WithMessage(err, "start command failed")
+	}
+
+	// Copy stdout to pipe
+	g, _ := errgroup.WithContext(s.ctx)
+	g.Go(func() error {
+		_, err = io.Copy(stdout, stdoutIn)
+		return err
+	})
+
+	if err := cmd.Wait(); err != nil {
+		warnings = append(warnings, errors.WithMessage(err, "nmap command failed").Error())
+	}
+	if err := g.Wait(); err != nil {
+		warnings = append(warnings, errors.WithMessage(err, "read from stdout failed").Error())
+	}
+	// Process nmap stderr output containing none-critical errors and warnings
+	// Everyone needs to check whether one or some of these warnings is a hard issue in their use case
+	if stderrBuf.Len() > 0 {
+		for _, v := range strings.Split(strings.Trim(stderrBuf.String(), "\n"), "\n") {
+			warnings = append(warnings, v)
+		}
+	}
+
+	// Check for warnings that will inevitable lead to parsing errors, hence, have priority
+	for _, warning := range warnings {
+		switch {
+		case strings.Contains(warning, "Malloc Failed!"):
+			return warnings, ErrMallocFailed
+		// TODO: Add cases for other known errors we might want to guard.
+		default:
+		}
+	}
+
+	// Return result, optional warnings but no error
+	return warnings, nil
+}
+
 // RunAsync runs nmap asynchronously and returns error.
 // TODO: RunAsync should return warnings as well.
 func (s *Scanner) RunAsync() error {

nmap_test.go

@@ -271,10 +271,10 @@ func TestRunWithProgress(t *testing.T) {
 				WithCustomArguments("tests/xml/scan_base.xml"),
 			},
 
-			compareWholeRun: true,
-			expectedResult: r,
+			compareWholeRun:  true,
+			expectedResult:   r,
 			expectedProgress: []float32{56.66, 81.95, 87.84, 94.43, 97.76, 97.76},
-			expectedErr: nil,
+			expectedErr:      nil,
 		},
 	}