path_attributes_test.go

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeNextHop(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeMED(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "Test #1",
			input: &PathAttribute{
				TypeCode: MEDAttr,
				Value:    uint32(1000),
			},
			expected: []byte{
				128,          // Attribute flags
				4,            // Type
				4,            // Length
				0, 0, 3, 232, // Value = 1000
			},
			expectedLen: 7,
		},
	}

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeMED(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeLocalPref(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "Test #1",
			input: &PathAttribute{
				TypeCode: LocalPrefAttr,
				Value:    uint32(1000),
			},
			expected: []byte{
				64,           // Attribute flags
				5,            // Type
				4,            // Length
				0, 0, 3, 232, // Value = 1000
			},
			expectedLen: 7,
		},
	}

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeLocalpref(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeAtomicAggregate(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "Test #1",
			input: &PathAttribute{
				TypeCode: AtomicAggrAttr,
			},
			expected: []byte{
				64, // Attribute flags
				6,  // Type
				0,  // Length
			},
			expectedLen: 3,
		},
	}

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeAtomicAggregate(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeAggregator(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "Test #1",
			input: &PathAttribute{
				TypeCode: AggregatorAttr,
				Value:    uint16(174),
			},
			expected: []byte{
				192,    // Attribute flags
				7,      // Type
				2,      // Length
				0, 174, // Value = 174
			},
			expectedLen: 5,
		},
	}

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeAggregator(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeASPath(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "Test #1",
			input: &PathAttribute{
				TypeCode: ASPathAttr,
				Value: ASPath{
					{
						Type: 2, // Sequence
						ASNs: []uint32{
							100, 200, 210,
						},
					},
				},
			},
			expected: []byte{
				64,     // Attribute flags
				2,      // Type
				8,      // Length
				2,      // AS_SEQUENCE
				3,      // ASN count
				0, 100, // ASN 100
				0, 200, // ASN 200
				0, 210, // ASN 210
			},
			expectedLen: 10,
		},
	}

	for _, test := range tests {
		buf := bytes.NewBuffer(nil)
		n := test.input.serializeASPath(buf)
		if n != test.expectedLen {
			t.Errorf("Unexpected length for test %q: %d", test.name, n)
			continue
		}

		assert.Equal(t, test.expected, buf.Bytes())
	}
}

func TestSerializeLargeCommunities(t *testing.T) {
	tests := []struct {
		name        string
		input       *PathAttribute
		expected    []byte
		expectedLen uint8
	}{
		{
			name: "2 large communities",
			input: &PathAttribute{
				TypeCode: LargeCommunityAttr,
				Value: []LargeCommunity{
					{
						GlobalAdministrator: 1,
						DataPart1:           2,
						DataPart2:           3,
					},
					{
						GlobalAdministrator: 4,
						DataPart1:           5,
						DataPart2:           6,
					},
				},
			},
			expected: []byte{
				0xe0,                                                                   // Attribute flags
				32,                                                                     // Type
				24,                                                                     // Length
				0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 6, // Communities (1, 2, 3), (4, 5, 6)
			},
			expectedLen: 24,
		},
		{
			name: "empty list of communities",
			input: &PathAttribute{
				TypeCode: LargeCommunityAttr,
				Value:    []LargeCommunity{},
			},
			expected:    []byte{},
			expectedLen: 0,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(te *testing.T) {
			buf := bytes.NewBuffer([]byte{})
			n := test.input.serializeLargeCommunities(buf)
			if n != test.expectedLen {
				t.Fatalf("Unexpected length for test %q: %d", test.name, n)
			}

			assert.Equal(t, test.expected, buf.Bytes())
		})
	}
}

func TestSerialize(t *testing.T) {
	tests := []struct {
		name     string
		msg      *BGPUpdate
		expected []byte
		wantFail bool
	}{
		{
			name: "Withdraw only",
			msg: &BGPUpdate{
				WithdrawnRoutes: &NLRI{
					IP:     strAddr("100.110.120.0"),
					Pfxlen: 24,
				},
			},
			expected: []byte{
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0, 27, // Length
				2,    // Msg Type
				0, 4, // Withdrawn Routes Length
				24, 100, 110, 120, // NLRI
				0, 0, // Total Path Attribute Length
			},
		},
		{
			name: "NLRI only",
			msg: &BGPUpdate{
				NLRI: &NLRI{
					IP:     strAddr("100.110.128.0"),
					Pfxlen: 17,
				},
			},
			expected: []byte{
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0, 27, // Length
				2,    // Msg Type
				0, 0, // Withdrawn Routes Length
				0, 0, // Total Path Attribute Length
				17, 100, 110, 128, // NLRI
			},
		},
		{
			name: "Path Attributes only",
			msg: &BGPUpdate{
				PathAttributes: &PathAttribute{
					Optional:   true,
					Transitive: true,
					TypeCode:   OriginAttr,
					Value:      uint8(0), // IGP
				},
			},
			expected: []byte{
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0, 27, // Length
				2,    // Msg Type
				0, 0, // Withdrawn Routes Length
				0, 4, // Total Path Attribute Length
				64, // Attr. Flags
				1,  // Attr. Type Code
				1,  // Length
				0,  // Value
			},
		},
		{
			name: "Full test",
			msg: &BGPUpdate{
				WithdrawnRoutes: &NLRI{
					IP:     strAddr("10.0.0.0"),
					Pfxlen: 8,
					Next: &NLRI{
						IP:     strAddr("192.168.0.0"),
						Pfxlen: 16,
					},
				},
				PathAttributes: &PathAttribute{
					TypeCode: OriginAttr,
					Value:    uint8(0),
					Next: &PathAttribute{
						TypeCode: ASPathAttr,
						Value: ASPath{
							{
								Type: 2,
								ASNs: []uint32{100, 155, 200},
							},
							{
								Type: 1,
								ASNs: []uint32{10, 20},
							},
						},
						Next: &PathAttribute{
							TypeCode: NextHopAttr,
							Value:    strAddr("10.20.30.40"),
							Next: &PathAttribute{
								TypeCode: MEDAttr,
								Value:    uint32(100),
								Next: &PathAttribute{
									TypeCode: LocalPrefAttr,
									Value:    uint32(500),
									Next: &PathAttribute{
										TypeCode: AtomicAggrAttr,
										Next: &PathAttribute{
											TypeCode: AggregatorAttr,
											Value:    uint16(200),
										},
									},
								},
							},
						},
					},
				},
				NLRI: &NLRI{
					IP:     strAddr("8.8.8.0"),
					Pfxlen: 24,
					Next: &NLRI{
						IP:     strAddr("185.65.240.0"),
						Pfxlen: 22,
					},
				},
			},
			expected: []byte{
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0, 86, // Length
				2, // Msg Type

				// Withdraws
				0, 5, // Withdrawn Routes Length
				8, 10, // Withdraw 10/8
				16, 192, 168, // Withdraw 192.168/16

				0, 50, // Total Path Attribute Length

				// ORIGIN
				64, // Attr. Flags
				1,  // Attr. Type Code
				1,  // Length
				0,  // Value
				// ASPath
				64,                     // Attr. Flags
				2,                      // Attr. Type Code
				14,                     // Attr. Length
				2,                      // Path Segment Type = AS_SEQUENCE
				3,                      // Path Segment Length
				0, 100, 0, 155, 0, 200, // ASNs
				1,            // Path Segment Type = AS_SET
				2,            // Path Segment Type = AS_SET
				0, 10, 0, 20, // ASNs
				// Next Hop
				64,             // Attr. Flags
				3,              // Attr. Type Code
				4,              // Length
				10, 20, 30, 40, // Next Hop Address
				// MED
				128,          // Attr. Flags
				4,            // Attr Type Code
				4,            // Length
				0, 0, 0, 100, // MED = 100
				// LocalPref
				64,           // Attr. Flags
				5,            // Attr. Type Code
				4,            // Length
				0, 0, 1, 244, // Localpref
				// Atomic Aggregate
				64, // Attr. Flags
				6,  // Attr. Type Code
				0,  // Length
				// Aggregator
				192,    // Attr. Flags
				7,      // Attr. Type Code
				2,      // Length
				0, 200, // Aggregator ASN = 200

				// NLRI
				24, 8, 8, 8, // 8.8.8.0/24
				22, 185, 65, 240, // 185.65.240.0/22
			},
		},
	}

	for _, test := range tests {
		res, err := test.msg.SerializeUpdate()
		if err != nil {
			if test.wantFail {
				continue
			}

			t.Errorf("Unexpected failure for test %q: %v", test.name, err)
			continue
		}

		if test.wantFail {
			t.Errorf("Unexpected success for test %q", test.name)
			continue
		}

		assert.Equalf(t, test.expected, res, "%s", test.name)
	}
}

func TestParseASPathStr(t *testing.T) {
	tests := []struct {
		name     string
		input    string
		wantFail bool
		expected *PathAttribute
	}{
		{
			name:     "Simple AS_SEQUENCE",
			input:    "3320 15169",
			wantFail: false,
			expected: &PathAttribute{
				TypeCode: ASPathAttr,
				Value: ASPath{
					ASPathSegment{
						Type: ASSequence,
						ASNs: []uint32{3320, 15169},
					},
				},
			},
		},
		{
			name:     "AS_SEQUENCE with more than 255 elements",
			input:    "123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123 123",
			wantFail: false,
			expected: &PathAttribute{
				TypeCode: ASPathAttr,
				Value: ASPath{
					ASPathSegment{
						Type: ASSequence,
						ASNs: []uint32{123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123},
					},
					ASPathSegment{
						Type: ASSequence,
						ASNs: []uint32{123, 123, 123, 123, 123},
					},
				},
			},
		},
		{
			name:     "AS_SET only",
			input:    "(3320 201701 15169)",
			wantFail: false,
			expected: &PathAttribute{
				TypeCode: ASPathAttr,
				Value: ASPath{
					ASPathSegment{
						Type: ASSet,
						ASNs: []uint32{3320, 201701, 15169},
					},
				},
			},
		},
		{
			name:     "Mixed AS Path",
			input:    "199714 51324 (3320 201701 15169)",
			wantFail: false,
			expected: &PathAttribute{
				TypeCode: ASPathAttr,
				Value: ASPath{
					ASPathSegment{
						Type: ASSequence,
						ASNs: []uint32{199714, 51324},
					},
					ASPathSegment{
						Type: ASSet,
						ASNs: []uint32{3320, 201701, 15169},
					},
				},
			},
		},
	}

	for _, test := range tests {
		res, err := ParseASPathStr(test.input)
		if err != nil {
			if test.wantFail {
				continue
			}

			t.Errorf("Unexpected failure for test %q: %v", test.name, err)
			continue
		}

		if test.wantFail {
			t.Errorf("Unexpected success for test %q", test.name)
			continue
		}

		assert.Equal(t, test.expected, res)
	}
}

func TestFourBytesToUint32(t *testing.T) {
	tests := []struct {
		name     string
		input    [4]byte
		expected uint32
	}{
		{
			name:     "Test #1",
			input:    [4]byte{0, 0, 0, 200},
			expected: 200,
		},
		{
			name:     "Test #2",
			input:    [4]byte{1, 0, 0, 200},
			expected: 16777416,
		},
	}

	for _, test := range tests {
		res := fourBytesToUint32(test.input)
		if res != test.expected {
			t.Errorf("Unexpected result for test %q: Got: %d Want: %d", test.name, res, test.expected)
		}
	}
}