Implement ECMP for unsafe_routes (#1332)

routing/balance_test.go

@@ -0,0 +1,144 @@
+package routing
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/slackhq/nebula/firewall"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPacketsAreBalancedEqually(t *testing.T) {
+
+	gateways := []Gateway{}
+
+	gw1Addr := netip.MustParseAddr("1.0.0.1")
+	gw2Addr := netip.MustParseAddr("1.0.0.2")
+	gw3Addr := netip.MustParseAddr("1.0.0.3")
+
+	gateways = append(gateways, NewGateway(gw1Addr, 1))
+	gateways = append(gateways, NewGateway(gw2Addr, 1))
+	gateways = append(gateways, NewGateway(gw3Addr, 1))
+
+	CalculateBucketsForGateways(gateways)
+
+	gw1count := 0
+	gw2count := 0
+	gw3count := 0
+
+	iterationCount := uint16(65535)
+	for i := uint16(0); i < iterationCount; i++ {
+		packet := firewall.Packet{
+			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
+			RemoteAddr: netip.MustParseAddr("10.0.0.1"),
+			LocalPort:  i,
+			RemotePort: 65535 - i,
+			Protocol:   6, // TCP
+			Fragment:   false,
+		}
+
+		selectedGw, ok := BalancePacket(&packet, gateways)
+		assert.True(t, ok)
+
+		switch selectedGw {
+		case gw1Addr:
+			gw1count += 1
+		case gw2Addr:
+			gw2count += 1
+		case gw3Addr:
+			gw3count += 1
+		}
+
+	}
+
+	// Assert packets are balanced, allow variation of up to 100 packets per gateway
+	assert.InDeltaf(t, iterationCount/3, gw1count, 100, "Expected %d +/- 100, but got %d", iterationCount/3, gw1count)
+	assert.InDeltaf(t, iterationCount/3, gw2count, 100, "Expected %d +/- 100, but got %d", iterationCount/3, gw1count)
+	assert.InDeltaf(t, iterationCount/3, gw3count, 100, "Expected %d +/- 100, but got %d", iterationCount/3, gw1count)
+
+}
+
+func TestPacketsAreBalancedByPriority(t *testing.T) {
+
+	gateways := []Gateway{}
+
+	gw1Addr := netip.MustParseAddr("1.0.0.1")
+	gw2Addr := netip.MustParseAddr("1.0.0.2")
+
+	gateways = append(gateways, NewGateway(gw1Addr, 10))
+	gateways = append(gateways, NewGateway(gw2Addr, 5))
+
+	CalculateBucketsForGateways(gateways)
+
+	gw1count := 0
+	gw2count := 0
+
+	iterationCount := uint16(65535)
+	for i := uint16(0); i < iterationCount; i++ {
+		packet := firewall.Packet{
+			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
+			RemoteAddr: netip.MustParseAddr("10.0.0.1"),
+			LocalPort:  i,
+			RemotePort: 65535 - i,
+			Protocol:   6, // TCP
+			Fragment:   false,
+		}
+
+		selectedGw, ok := BalancePacket(&packet, gateways)
+		assert.True(t, ok)
+
+		switch selectedGw {
+		case gw1Addr:
+			gw1count += 1
+		case gw2Addr:
+			gw2count += 1
+		}
+
+	}
+
+	iterationCountAsFloat := float32(iterationCount)
+
+	assert.InDeltaf(t, iterationCountAsFloat*(2.0/3.0), gw1count, 100, "Expected %d +/- 100, but got %d", iterationCountAsFloat*(2.0/3.0), gw1count)
+	assert.InDeltaf(t, iterationCountAsFloat*(1.0/3.0), gw2count, 100, "Expected %d +/- 100, but got %d", iterationCountAsFloat*(1.0/3.0), gw2count)
+}
+
+func TestBalancePacketDistributsRandomlyAndReturnsFalseIfBucketsNotCalculated(t *testing.T) {
+	gateways := []Gateway{}
+
+	gw1Addr := netip.MustParseAddr("1.0.0.1")
+	gw2Addr := netip.MustParseAddr("1.0.0.2")
+
+	gateways = append(gateways, NewGateway(gw1Addr, 10))
+	gateways = append(gateways, NewGateway(gw2Addr, 5))
+
+	iterationCount := uint16(65535)
+	gw1count := 0
+	gw2count := 0
+
+	for i := uint16(0); i < iterationCount; i++ {
+		packet := firewall.Packet{
+			LocalAddr:  netip.MustParseAddr("192.168.1.1"),
+			RemoteAddr: netip.MustParseAddr("10.0.0.1"),
+			LocalPort:  i,
+			RemotePort: 65535 - i,
+			Protocol:   6, // TCP
+			Fragment:   false,
+		}
+
+		selectedGw, ok := BalancePacket(&packet, gateways)
+		assert.False(t, ok)
+
+		switch selectedGw {
+		case gw1Addr:
+			gw1count += 1
+		case gw2Addr:
+			gw2count += 1
+		}
+
+	}
+
+	assert.Equal(t, int(iterationCount), (gw1count + gw2count))
+	assert.NotEqual(t, 0, gw1count)
+	assert.NotEqual(t, 0, gw2count)
+
+}