fix marshaling issue in coap

modules/coap/message/decoder.go

@@ -6,9 +6,9 @@ import (
 )
 
 const (
-	OptionBlock1        = 27 // CoAP Block1 Option Number
-	OptionBlock2        = 23 // CoAP Block2 Option Number
-	OptionContentFormat = 12 // CoAP Content-Format Option Number
+	OptionBlock1        uint16 = 27 // CoAP Block1 Option Number
+	OptionBlock2        uint16 = 23 // CoAP Block2 Option Number
+	OptionContentFormat uint16 = 12 // CoAP Content-Format Option Number
 )
 
 var (
@@ -43,12 +43,14 @@ func (d *decoder) Decode(data []byte, msg *Message) error {
 	}
 	msg.Options = opts
 
-	var payload = new(Payload)
-	cType := uint16(opts[OptionContentFormat].Value[0])
-	if err := payload.Unmarshal(buf, cType); err != nil {
-		return err
+	if cOpt, ok := opts[OptionContentFormat]; ok {
+		var payload = new(Payload)
+		cType := uint16(cOpt.Value[0])
+		if err := payload.Unmarshal(buf, cType); err != nil {
+			return err
+		}
+		msg.Payload = payload
 	}
-	msg.Payload = payload
 
 	for _, oID := range []uint16{OptionBlock1, OptionBlock2} {
 		if opt, ok := opts[oID]; ok {

modules/coap/message/option.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 )
 
@@ -99,32 +100,31 @@ var optionDefinitions = map[uint16]OptDef{
 
 type Options map[uint16]*Option
 
-func (o *Options) Unmarshal(buf *bytes.Buffer) (err error) {
+func (o *Options) Unmarshal(buf *bytes.Buffer) error {
 	prevOpt := 0
 	for buf.Len() > 0 {
 		b, err := buf.ReadByte()
 		if err == io.EOF {
-			break
+			return err
 		}
 
 		delta, length := int(b>>4), int(b&0x0F)
 		if delta == 0x0F && length == 0x0F {
-			break
+			return fmt.Errorf("invalid delta")
 		}
 
 		delta, err = o.parseExtOpt(buf, delta)
 		if err != nil {
-			break
+			return err
 		}
 
 		length, err = o.parseExtOpt(buf, length)
 		if err != nil {
-			break
+			return err
 		}
 
 		if buf.Len() < length {
-			err = ErrSmallBuffer
-			break
+			return ErrSmallBuffer
 		}
 		data := buf.Next(length)
 		optID := prevOpt + delta

modules/coap/scanner.go

@@ -4,6 +4,7 @@ import (
 	"encoding/csv"
 	"log"
 	"strings"
+	"time"
 
 	"github.com/zmap/zgrab2"
 )
@@ -102,6 +103,11 @@ func (scanner *Scanner) Init(flags zgrab2.ScanFlags) error {
 		return err
 	}
 	scanner.paths = paths
+
+	if fl.Timeout <= 0 {
+		fl.Timeout = 10 * time.Second
+	}
+
 	scanner.probe = newProbeBuilder(fl.Timeout)
 
 	return nil
@@ -139,9 +145,9 @@ func (scanner *Scanner) Scan(t zgrab2.ScanTarget) (zgrab2.ScanStatus, interface{
 	scan := scanner.newCoAPscan(&t)
 	err := scan.Grab()
 	if err != nil {
-		return err.Unpack(&scan.results)
+		return err.Unpack(scan.results)
 	}
-	return zgrab2.SCAN_SUCCESS, &scan.results, nil
+	return zgrab2.SCAN_SUCCESS, scan.results, nil
 }
 
 // RegisterModule is called by modules/coap.go to register this module with the