Merge pull request #175 from sbezverk/issue_171

issue #171 and SID to uint32

pkg/sr/sr-adjacencysid.go

@@ -30,7 +30,7 @@ func (a *AdjacencySIDTLV) MarshalJSON() ([]byte, error) {
 		return json.Marshal(struct {
 			Flags  *AdjISISFlags `json:"flags,omitempty"`
 			Weight uint8         `json:"weight"`
-			SID    uint32        `json:"prefix_sid,omitempty"`
+			SID    uint32        `json:"sid,omitempty"`
 		}{
 			Flags:  f,
 			Weight: a.Weight,

pkg/sr/sr-peersid.go

@@ -1,6 +1,8 @@
 package sr
 
 import (
+	"encoding/binary"
+	"encoding/json"
 	"fmt"
 
 	"github.com/golang/glog"
@@ -32,14 +34,22 @@ func UnmarshalPeerFlags(b []byte) (*PeerFlags, error) {
 type PeerSID struct {
 	Flags  *PeerFlags `json:"flags"`
 	Weight uint8      `json:"weight"`
-	SID    []byte     `json:"prefix_sid,omitempty"`
+	SID    uint32     `json:"sid,omitempty"`
+}
+
+func (p *PeerSID) String() string {
+	s, _ := json.Marshal(p)
+	return string(s)
 }
 
 // UnmarshalPeerSID builds PeerSID TLV Object
 func UnmarshalPeerSID(b []byte) (*PeerSID, error) {
 	if glog.V(6) {
 		glog.Infof("Peer SID TLV Raw: %s", tools.MessageHex(b))
 	}
+	if len(b) != 7 && len(b) != 8 {
+		return nil, fmt.Errorf("invalid length %d of data to decode peer sid tlv", len(b))
+	}
 	psid := PeerSID{}
 	p := 0
 	f, err := UnmarshalPeerFlags(b[p : p+1])
@@ -51,10 +61,28 @@ func UnmarshalPeerSID(b []byte) (*PeerSID, error) {
 	psid.Weight = b[p]
 	p++
 	// SID length would be Length of b - Flags 1 byte - Weight 1 byte - 2 bytes Reserved
-	sl := len(b) - 4
-	psid.SID = make([]byte, len(b)-4)
 	p += 2
-	copy(psid.SID, b[p:p+sl])
+	l := len(b) - 4
+	s := make([]byte, 4)
+	switch l {
+	case 3:
+		if !psid.Flags.VFlag || !psid.Flags.LFlag {
+			// When sid is 3 bytes, V and L flags MUST be set to "true", if not, error out
+			return nil, fmt.Errorf("sid length is 3 bytes but V flag is NOT set to \"true\"")
+		}
+		copy(s[1:], b[p:p+3])
+		// Since label uses only 20 bits for label, clear first 4 bits of s[1]
+		s[1] &= 0x0f
+	case 4:
+		if psid.Flags.VFlag {
+			// When sid is 4 bytes, V flag must NOT be set to "true", if not, error out
+			return nil, fmt.Errorf("sid length is 4 bytes but V flag is set to \"true\"")
+		}
+		copy(s, b[p:p+4])
+	default:
+		return nil, fmt.Errorf("software bug in peer sid processing logic, byte slice: %s", tools.MessageHex(b))
+	}
+	psid.SID = binary.BigEndian.Uint32(s)
 
 	return &psid, nil
 }

pkg/sr/sr-peersid_test.go

@@ -0,0 +1,45 @@
+package sr
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/go-test/deep"
+)
+
+func TestUnmarshalPeerSID(t *testing.T) {
+	tests := []struct {
+		name   string
+		input  []byte
+		expect *PeerSID
+	}{
+		{
+			name:  "issue 171",
+			input: []byte{0xD0, 0x00, 0x00, 0x00, 0x00, 0x3A, 0xA8},
+			expect: &PeerSID{
+				Flags: &PeerFlags{
+					VFlag: true,
+					LFlag: true,
+					PFlag: true,
+				},
+				Weight: 0,
+				SID:    15016,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r, err := UnmarshalPeerSID(tt.input)
+			if err != nil {
+				t.Fatalf("failed with error: %+v", err)
+			}
+			if !reflect.DeepEqual(tt.expect, r) {
+				t.Logf("Diffs: %+v", deep.Equal(tt.expect, r))
+				t.Fatalf("expected peer sid %+v does not match to he actual %+v", tt.expect, r)
+			}
+			if err == nil {
+				t.Logf("Peer SID: %s", r)
+			}
+		})
+	}
+}