sbr: Add test for preserveDefaultRoutes option

Add test that verifies the preserveDefaultRoutes option correctly maintains
subnet routes in the main routing table with source IP hints for destination-
based routing.

The test verifies:
- Source-based routing rules are created (table 100)
- Subnet routes exist in main table with source hints
- Subnet routes also exist in table 100
- Default routes exist in table 100

This enables both explicit source routing (ping -I) and destination-based
routing (plain ping) to work simultaneously.

Signed-off-by: David Whyte-Gray <[email protected]>

Author: dagrayvid

plugins/meta/sbr/sbr_linux_test.go

@@ -691,8 +691,6 @@ var _ = Describe("sbr test", func() {
 		}
 		Expect(foundDefaultRoute).To(BeTrue(), "Expected to find default route with static gateway")
 	})
-<<<<<<< Updated upstream
-=======
 
 	It("Works with preserveDefaultRoutes enabled", func() {
 		ifname := "net1"
@@ -753,7 +751,7 @@ var _ = Describe("sbr test", func() {
 		for _, route := range devNet1.Routes {
 			// Look for subnet route (192.168.1.0/24) in main table with source hint
 			if route.Dst != nil && route.Dst.IP.Equal(net.IPv4(192, 168, 1, 0)) &&
-			   route.Dst.Mask.String() == "ffffff00" {
+				route.Dst.Mask.String() == "ffffff00" {
 				if route.Table == 254 || route.Table == 0 { // 0 is treated as main
 					Expect(route.Src.String()).To(Equal("192.168.1.209"),
 						"Subnet route in main table should have source IP hint")
@@ -779,5 +777,4 @@ var _ = Describe("sbr test", func() {
 		Expect(foundDefaultRouteInTable100).To(BeTrue(),
 			"Expected default route in table 100")
 	})
->>>>>>> Stashed changes
 })