Add messagetype, vendor name registries and lookups

go.mod

@@ -1,7 +1,17 @@
 module github.com/farsightsec/go-nmsg
 
+go 1.18
+
 require (
 	github.com/dnstap/golang-dnstap v0.4.0
 	google.golang.org/protobuf v1.25.0
 	gopkg.in/yaml.v2 v2.4.0
 )
+
+require (
+	github.com/farsightsec/golang-framestream v0.3.0 // indirect
+	github.com/miekg/dns v1.1.31 // indirect
+	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 // indirect
+	golang.org/x/net v0.0.0-20190923162816-aa69164e4478 // indirect
+	golang.org/x/sys v0.8.0 // indirect
+)

go.sum

@@ -51,8 +51,9 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe h1:6fAMxZRR6sl1Uq8U61gxU+kPTs2tR8uOySCbBP7BN/M=
 golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=

nmsg_base/base.go

@@ -68,6 +68,7 @@ func (d *DnsObs) GetVid() uint32     { return 1 }
 func (d *DnsObs) GetMsgtype() uint32 { return 14 }
 
 func init() {
+	nmsg.RegisterVendor("base", 1)
 	nmsg.Register(&Ncap{})
 	nmsg.Register(&Email{})
 	nmsg.Register(&Linkpair{})

register.go

@@ -11,9 +11,14 @@ package nmsg
 import (
 	"fmt"
 	"reflect"
+	"strings"
 )
 
 var types map[uint32]map[uint32]reflect.Type
+var typesByName map[uint32]map[string]uint32
+
+var vendors map[uint32]string
+var vids map[string]uint32
 
 // Register records the supplied message's type, indexed by its MessageType
 // and VendorID, for the purposes of decoding protobuf-encoded payloads.
@@ -24,6 +29,7 @@ var types map[uint32]map[uint32]reflect.Type
 func Register(m Message) {
 	if types == nil {
 		types = make(map[uint32]map[uint32]reflect.Type)
+		typesByName = make(map[uint32]map[string]uint32)
 	}
 	vid := m.GetVid()
 	v, ok := types[vid]
@@ -34,12 +40,39 @@ func Register(m Message) {
 
 	msgtype := m.GetMsgtype()
 	v[msgtype] = reflect.TypeOf(m)
+
+	name := strings.ToLower(v[msgtype].Elem().Name())
+
+	tn, ok := typesByName[vid]
+	if !ok {
+		tn = make(map[string]uint32)
+		typesByName[vid] = tn
+	}
+
+	tn[name] = msgtype
+}
+
+// RegisterVendor records an association between the vendor named `vname`
+// and a numeric vendor id `vid`
+func RegisterVendor(vname string, vid uint32) {
+	if vendors == nil {
+		vendors = make(map[uint32]string)
+		vids = make(map[string]uint32)
+	}
+	vendors[vid] = vname
+	vids[vname] = vid
+}
+
+type unknownVid uint32
+
+func (v unknownVid) Error() string {
+	return fmt.Sprintf("Vendor %d not registered.", v)
 }
 
-type unknownVendor uint32
+type unknownVendor string
 
 func (v unknownVendor) Error() string {
-	return fmt.Sprintf("Vendor %d has no registered Msgtypes.", v)
+	return fmt.Sprintf("Vendor '%s' not registered.", string(v))
 }
 
 type unknownMsgtype struct{ vid, msgtype uint32 }
@@ -53,7 +86,7 @@ func (t unknownMsgtype) Error() string {
 func NewMessage(vid, msgtype uint32) (Message, error) {
 	v, ok := types[vid]
 	if !ok {
-		return nil, unknownVendor(vid)
+		return nil, unknownVid(vid)
 	}
 
 	t, ok := v[msgtype]
@@ -63,3 +96,66 @@ func NewMessage(vid, msgtype uint32) (Message, error) {
 
 	return reflect.New(t.Elem()).Interface().(Message), nil
 }
+
+// VendorByname returns the numeric vendor id registered for the given
+// name, if any.
+func VendorByName(vname string) (uint32, error) {
+	vid, ok := vids[vname]
+	if !ok {
+		return 0, unknownVendor(vname)
+	}
+	return vid, nil
+}
+
+// VendorName returns the vendor name registered for the given
+// numeric vid, if any.
+func VendorName(vid uint32) (string, error) {
+	vname, ok := vendors[vid]
+	if !ok {
+		return "", unknownVid(vid)
+	}
+	return vname, nil
+}
+
+// MessageTypeByName returns the numeric vendor id and message type
+// for the given vendor name and message type name, for the purposes
+// of creating a new message with NewMessage().
+func MessageTypeByName(vname string, mname string) (vid uint32, mtype uint32, err error) {
+	var ok bool
+
+	vid, err = VendorByName(vname)
+	if err != nil {
+		return
+	}
+
+	mtype, ok = typesByName[vid][strings.ToLower(mname)]
+	if !ok {
+		err = fmt.Errorf("Unknown message type '%s' for vendor '%s'", mname, vname)
+	}
+	return
+}
+
+// MessageTypeName returns a vendor and message type name for a given
+// numeric vendor id and message type, if any
+func MessageTypeName(vid uint32, msgtype uint32) (vname string, mname string, err error) {
+	var ok bool
+	vname, err = VendorName(vid)
+	if err != nil {
+		return
+	}
+
+	v, ok := types[vid]
+	if !ok {
+		err = unknownVid(vid)
+		return
+	}
+
+	t, ok := v[msgtype]
+	if !ok {
+		err = unknownMsgtype{vid, msgtype}
+		return
+	}
+
+	mname = strings.ToLower(t.Elem().Name())
+	return
+}

register_test.go

@@ -0,0 +1,33 @@
+package nmsg_test
+
+import (
+	"github.com/farsightsec/go-nmsg"
+	_ "github.com/farsightsec/go-nmsg/nmsg_base"
+	"testing"
+)
+
+func TestRegisterVendor(t *testing.T) {
+	vname, err := nmsg.VendorName(1)
+	if err != nil || vname != "base" {
+		t.Errorf("VendorName(1): %s, %v", vname, err)
+	}
+
+	vid, err := nmsg.VendorByName("base")
+	if err != nil || vid != 1 {
+		t.Errorf("VendorByName(base): %d, %v", vid, err)
+	}
+}
+
+func TestRegisterMessageByName(t *testing.T) {
+	vid, msgtype, err := nmsg.MessageTypeByName("base", "ncap")
+	if err != nil || vid != 1 || msgtype != 1 {
+		t.Errorf("MessageTypeByName(base,ncap): %d, %d, %v", vid, msgtype, err)
+	}
+}
+
+func TestRegisterMessageName(t *testing.T) {
+	vname, mname, err := nmsg.MessageTypeName(1, 1)
+	if err != nil || vname != "base" || mname != "ncap" {
+		t.Errorf("MessageTypeByName(base,ncap): %s, %s, %v", vname, mname, err)
+	}
+}