Appease the linter

Author: nicholasberlin

packetbeat/protos/nfs/request_handler.go

@@ -240,12 +240,22 @@ func (r *rpc) handleReply(xid string, xdr *xdr, ts time.Time, tcptuple *common.T
 	// get cached request
 	v := r.callsSeen.Delete(reqID)
 	if v != nil {
-		nfs := v.(*nfs)
+		nfs, ok := v.(*nfs)
+		if !ok {
+			logp.Warn("nfs: failed to assert nfs interface")
+			return
+
+		}
 		nfs.pbf.Event.End = ts
 		nfs.pbf.Destination.Bytes = int64(xdr.size())
 
 		fields := nfs.event.Fields
-		rpcInfo := fields["rpc"].(mapstr.M)
+		rpcInfo, ok := fields["rpc"].(mapstr.M)
+		if !ok {
+			logp.Warn("nfs: failed to assert map[string]")
+			return
+
+		}
 		statusVal, err := xdr.getUInt()
 		if dropMalformed("rpc accept status", err) {
 			return
@@ -259,7 +269,12 @@ func (r *rpc) handleReply(xid string, xdr *xdr, ts time.Time, tcptuple *common.T
 
 		// populate nfs info for successfully executed requests
 		if status == 0 {
-			nfsInfo := fields["nfs"].(mapstr.M)
+			nfsInfo, ok := fields["nfs"].(mapstr.M)
+			if !ok {
+				logp.Warn("nfs: failed to assert map[string]")
+				return
+
+			}
 			nfsStatus, err := nfs.getNFSReplyStatus(xdr)
 			if dropMalformed("nfs reply status", err) {
 				return

packetbeat/protos/nfs/rpc.go

@@ -92,7 +92,9 @@ func New(
 }
 
 func (r *rpc) init(results protos.Reporter, config *rpcConfig) error {
-	r.setFromConfig(config)
+	if err := r.setFromConfig(config); err != nil {
+		return err
+	}
 	r.results = results
 	r.callsSeen = common.NewCacheWithRemovalListener(
 		r.transactionTimeout,
@@ -214,7 +216,7 @@ func (r *rpc) handleRPCFragment(
 			break
 		}
 
-		marker := uint32(binary.BigEndian.Uint32(st.rawData[0:4]))
+		marker := binary.BigEndian.Uint32(st.rawData[0:4])
 		size := int(marker & rpcSizeMask)
 		islast := (marker & rpcLastFrag) != 0
 

packetbeat/protos/nfs/xdr.go

@@ -23,14 +23,14 @@ import (
 )
 
 const (
-	maxOpaque uint32 = 1 << 20
-	maxVector uint32 = 1 << 15
+	maxOpaque int = 1 << 20
+	maxVector int = 1 << 15
 )
 
 // XDR maps the External Data Representation
 type xdr struct {
 	data   []byte
-	offset uint32
+	offset int
 }
 
 func newXDR(data []byte) *xdr {
@@ -47,7 +47,7 @@ func (r *xdr) size() int {
 }
 
 func (r *xdr) getUInt() (uint32, error) {
-	if int(r.offset)+4 > len(r.data) {
+	if r.offset+4 > len(r.data) {
 		return 0, fmt.Errorf("xdr: truncated uint32")
 	}
 	i := binary.BigEndian.Uint32(r.data[r.offset : r.offset+4])
@@ -56,7 +56,7 @@ func (r *xdr) getUInt() (uint32, error) {
 }
 
 func (r *xdr) getUHyper() (uint64, error) {
-	if int(r.offset)+8 > len(r.data) {
+	if r.offset+8 > len(r.data) {
 		return 0, fmt.Errorf("xdr: truncated uint64")
 	}
 	i := binary.BigEndian.Uint64(r.data[r.offset : r.offset+8])
@@ -72,24 +72,24 @@ func (r *xdr) getString() (string, error) {
 	return string(b), nil
 }
 
-func (r *xdr) getOpaque(length uint32) ([]byte, error) {
-	if length > maxOpaque {
+func (r *xdr) getOpaque(length int) ([]byte, error) {
+	if length < 0 || length > maxOpaque {
 		return nil, fmt.Errorf("xdr: opaque length %d exceeds limit", length)
 	}
 
-	start := int(r.offset)
-	end := start + int(length)
+	start := r.offset
+	end := start + length
 	if end > len(r.data) {
 		return nil, fmt.Errorf("xdr: opaque length %d exceeds buffer", length)
 	}
 
-	padding := int((4 - (length & 3)) & 3)
+	padding := (4 - (length & 3)) & 3
 	if end+padding > len(r.data) {
 		return nil, fmt.Errorf("xdr: opaque padding exceeds buffer")
 	}
 
 	b := r.data[start:end]
-	r.offset = uint32(end + padding)
+	r.offset = end + padding
 	return b, nil
 }
 
@@ -98,15 +98,15 @@ func (r *xdr) getDynamicOpaque() ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	return r.getOpaque(l)
+	return r.getOpaque(int(l))
 }
 
 func (r *xdr) getUIntVector() ([]uint32, error) {
 	l, err := r.getUInt()
 	if err != nil {
 		return nil, err
 	}
-	if l > maxVector {
+	if int(l) > maxVector {
 		return nil, fmt.Errorf("xdr: vector length %d exceeds limit", l)
 	}
 	v := make([]uint32, int(l))

packetbeat/protos/nfs/xdr_test.go

@@ -163,6 +163,11 @@ func TestXdrDecodingFailures(t *testing.T) {
 	_, err = xdr.getOpaque(maxOpaque + 1)
 	require.Error(t, err)
 
+	b := make([]byte, maxOpaque+1)
+	xdr = makeXDR(b)
+	_, err = xdr.getOpaque(-1)
+	require.Error(t, err)
+
 	b = make([]byte, maxOpaque-1)
 	xdr = makeXDR(b)
 	_, err = xdr.getOpaque(maxOpaque)