diff --git a/protocols/bgp/packet/bgp.go b/protocols/bgp/packet/bgp.go
index 41a2113f8e6cb85cb0250d0333908071dc03fd79..c3a80b93aa666e18525e702d12530d66381c36c9 100644
--- a/protocols/bgp/packet/bgp.go
+++ b/protocols/bgp/packet/bgp.go
@@ -51,13 +51,14 @@ const (
MalformedASPath = 11
// Attribute Type Codes
- OriginAttr = 1
- ASPathAttr = 2
- NextHopAttr = 3
- MEDAttr = 4
- LocalPrefAttr = 5
- AtomicAggrAttr = 6
- AggregatorAttr = 7
+ OriginAttr = 1
+ ASPathAttr = 2
+ NextHopAttr = 3
+ MEDAttr = 4
+ LocalPrefAttr = 5
+ AtomicAggrAttr = 6
+ AggregatorAttr = 7
+ CommunitiesAttr = 8
// ORIGIN values
IGP = 0
diff --git a/protocols/bgp/packet/decoder_test.go b/protocols/bgp/packet/decoder_test.go
index a69b4acbcc8e985fad6a9a58637214d4c3496c49..c2222e6da95735a9faeedbb5db8cc12fbe34fb74 100644
--- a/protocols/bgp/packet/decoder_test.go
+++ b/protocols/bgp/packet/decoder_test.go
@@ -651,7 +651,6 @@ func TestDecodeUpdateMsg(t *testing.T) {
3, // Attribute Type code (Next Hop)
4, // Length
10, 11, 12, 13, // Next Hop
-
},
wantFail: false,
expected: &BGPUpdate{
@@ -745,7 +744,6 @@ func TestDecodeUpdateMsg(t *testing.T) {
4, // Attribute Type code (Next Hop)
4, // Length
0, 0, 1, 0, // MED 256
-
},
wantFail: false,
expected: &BGPUpdate{
@@ -852,7 +850,6 @@ func TestDecodeUpdateMsg(t *testing.T) {
5, // Attribute Type code (Local Pref)
4, // Length
0, 0, 1, 0, // Local Pref 256
-
},
wantFail: false,
expected: &BGPUpdate{
@@ -1262,6 +1259,94 @@ func TestDecodeUpdateMsg(t *testing.T) {
},
},
},
+ {
+ // 2 withdraws with two path attributes (Communities + Origin), valid update
+ testNum: 17,
+ input: []byte{0, 5, 8, 10, 16, 192, 168,
+ 0, 16, // Total Path Attribute Length
+
+ 0, // Attribute flags
+ 8, // Attribute Type code (Community)
+ 8, // Length
+ 0, 0, 1, 0, // Arbitrary Community
+ 0, 0, 1, 1, // Arbitrary Community
+
+ 255, // Attribute flags
+ 1, // Attribute Type code (ORIGIN)
+ 0, 1, // Length
+ 2, // INCOMPLETE
+
+ },
+ wantFail: false,
+ expected: &BGPUpdate{
+ WithdrawnRoutesLen: 5,
+ WithdrawnRoutes: &NLRI{
+ IP: strAddr("10.0.0.0"),
+ Pfxlen: 8,
+ Next: &NLRI{
+ IP: strAddr("192.168.0.0"),
+ Pfxlen: 16,
+ },
+ },
+ TotalPathAttrLen: 16,
+ PathAttributes: &PathAttribute{
+ Optional: false,
+ Transitive: false,
+ Partial: false,
+ ExtendedLength: false,
+ Length: 8,
+ TypeCode: 8,
+ Value: []uint32{256, 257},
+ Next: &PathAttribute{
+ Optional: true,
+ Transitive: true,
+ Partial: true,
+ ExtendedLength: true,
+ Length: 1,
+ TypeCode: 1,
+ Value: uint8(2),
+ },
+ },
+ },
+ },
+ {
+ // 2 withdraws with two path attributes (ORIGIN + Community), invalid update (too short community)
+ testNum: 18,
+ input: []byte{0, 5, 8, 10, 16, 192, 168,
+ 0, 11, // Total Path Attribute Length
+
+ 255, // Attribute flags
+ 1, // Attribute Type code (ORIGIN)
+ 0, 1, // Length
+ 2, // INCOMPLETE
+
+ 0, // Attribute flags
+ 8, // Attribute Type code (Community)
+ 3, // Length
+ 0, 0, 1, // Arbitrary Community
+ },
+ wantFail: true,
+ expected: nil,
+ },
+ {
+ // 2 withdraws with two path attributes (ORIGIN + Community), invalid update (too long community)
+ testNum: 19,
+ input: []byte{0, 5, 8, 10, 16, 192, 168,
+ 0, 13, // Total Path Attribute Length
+
+ 255, // Attribute flags
+ 1, // Attribute Type code (ORIGIN)
+ 0, 1, // Length
+ 2, // INCOMPLETE
+
+ 0, // Attribute flags
+ 8, // Attribute Type code (Community)
+ 5, // Length
+ 0, 0, 1, 0, 1, // Arbitrary Community
+ },
+ wantFail: true,
+ expected: nil,
+ },
}
for _, test := range tests {
diff --git a/protocols/bgp/packet/path_attributes.go b/protocols/bgp/packet/path_attributes.go
index 4db07c1d9f89b69ff292c7167228b3bfd47df3cf..846767989f400f1ede2fcf1e2c9202f33ad10974 100644
--- a/protocols/bgp/packet/path_attributes.go
+++ b/protocols/bgp/packet/path_attributes.go
@@ -84,6 +84,10 @@ func decodePathAttr(buf *bytes.Buffer) (pa *PathAttribute, consumed uint16, err
}
case AtomicAggrAttr:
// Nothing to do for 0 octet long attribute
+ case CommunitiesAttr:
+ if err := pa.decodeCommunities(buf); err != nil {
+ return nil, consumed, fmt.Errorf("Failed to decode Community: %v", err)
+ }
default:
if err := pa.decodeUnknown(buf); err != nil {
return nil, consumed, fmt.Errorf("Failed to decode unknown attribute: %v", err)
@@ -227,6 +231,27 @@ func (pa *PathAttribute) decodeAggregator(buf *bytes.Buffer) error {
return dumpNBytes(buf, pa.Length-p)
}
+func (pa *PathAttribute) decodeCommunities(buf *bytes.Buffer) error {
+ if pa.Length%4 != 0 {
+ return fmt.Errorf("Unable to read community path attribute length %d is not divisible by 4", pa.Length)
+ }
+ comNumber := pa.Length / 4
+ var com = make([]uint32, comNumber)
+ for i := uint16(0); i < comNumber; i++ {
+ c := [4]byte{}
+ n, err := buf.Read(c[:])
+ if err != nil {
+ return err
+ }
+ if n != 4 {
+ return fmt.Errorf("Unable to read next hop: buf.Read read %d bytes", n)
+ }
+ com[i] = fourBytesToUint32(c)
+ }
+ pa.Value = com
+ return nil
+}
+
func (pa *PathAttribute) setLength(buf *bytes.Buffer) (int, error) {
bytesRead := 0
if pa.ExtendedLength {
diff --git a/protocols/bgp/server/fsm.go b/protocols/bgp/server/fsm.go
index fc342e821871667f3d4fe7aab18e5d50e225674a..e20efb18015ea38b07587d043f76cdbfa531bba8 100644
--- a/protocols/bgp/server/fsm.go
+++ b/protocols/bgp/server/fsm.go
@@ -790,7 +790,7 @@ func (fsm *FSM) established() int {
case recvMsg := <-fsm.msgRecvCh:
msg, err := packet.Decode(bytes.NewBuffer(recvMsg.msg))
if err != nil {
- fmt.Printf("Failed to decode BGP message: %v\n", recvMsg.msg)
+ fmt.Printf("Failed to decode BGP message: %v msg: %v\n", err, recvMsg.msg)
switch bgperr := err.(type) {
case packet.BGPError:
sendNotification(fsm.con, bgperr.ErrorCode, bgperr.ErrorSubCode)