Don't fail when trying to add routes that already exist.

Previously, we suppressed failures for the special case of
requestRouteToHost() being called multiple times. Turns out that other
parts of the system also try to add duplicate routes, so just suppress
EEXIST errors in general (as far as adding routes is concerned). For
example, this happens when the WiFi P2P DHCP client renews its lease
and blindly requests to add a route that it had already added before.

(cherry picked from commit 64166e7666e3cc7f4b9c715f2b4e19d28ae44c5a)

Bug: 17205769
Change-Id: I11d50052f616cb48a912d647b8024ccef01b736d

1 files changed, 2 insertions, 5 deletions

diff --git a/server/RouteController.cpp b/server/RouteController.cpp
index 4cb145b2b..56e3c2866 100644
--- a/server/RouteController.cpp
+++ b/server/RouteController.cpp
@@ -815,11 +815,8 @@ WARN_UNUSED_RESULT int modifyRoute(uint16_t action, const char* interface, const
     }
 
     int ret = modifyIpRoute(action, table, interface, destination, nexthop);
-    // We allow apps to call requestRouteToHost() multiple times with the same route, so ignore
-    // EEXIST failures when adding routes to legacy tables.
-    if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST &&
-                 (tableType == RouteController::LEGACY_NETWORK ||
-                  tableType == RouteController::LEGACY_SYSTEM))) {
+    // Trying to add a route that already exists shouldn't cause an error.
+    if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST)) {
         return ret;
     }