[client] Improve route acl (#2705)

- Update nftables library to v0.2.0
- Mark traffic that was originally destined for local and applies the input rules in the forward chain if said traffic was redirected (e.g. by Docker)
- Add nft rules to internal map only if flush was successful
- Improve error message if handle is 0 (= not found or hasn't been refreshed)
- Add debug logging when route rules are added
- Replace nftables userdata (rule ID) with a rule hash

client/firewall/nftables/router_linux_test.go

@@ -314,6 +314,10 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 			ruleKey, err := r.AddRouteFiltering(tt.sources, tt.destination, tt.proto, tt.sPort, tt.dPort, tt.action)
 			require.NoError(t, err, "AddRouteFiltering failed")
 
+			t.Cleanup(func() {
+				require.NoError(t, r.DeleteRouteRule(ruleKey), "Failed to delete rule")
+			})
+
 			// Check if the rule is in the internal map
 			rule, ok := r.rules[ruleKey.GetRuleID()]
 			assert.True(t, ok, "Rule not found in internal map")
@@ -346,10 +350,6 @@ func TestRouter_AddRouteFiltering(t *testing.T) {
 
 			// Verify actual nftables rule content
 			verifyRule(t, nftRule, tt.sources, tt.destination, tt.proto, tt.sPort, tt.dPort, tt.direction, tt.action, tt.expectSet)
-
-			// Clean up
-			err = r.DeleteRouteRule(ruleKey)
-			require.NoError(t, err, "Failed to delete rule")
 		})
 	}
 }