From 59352bd4b03b41a286a347e5f09671e1e0531376 Mon Sep 17 00:00:00 2001 From: Thomas Haller Date: Mon, 22 Dec 2014 17:59:16 +0100 Subject: [PATCH] platform: workaround deletion of IPv4 route with metric 0 Deleting routes with metric 0 might end up deleting other routes with a different metric. Workaround this in platform to only delete a route with metric 0 if such a route can be found prior to deletion. Don't only look into the cache (which might be out of date). Instead refetch the route we are about to delete to be sure. There is still a race that we might end up deleting the wrong route. https://bugzilla.gnome.org/show_bug.cgi?id=741871 https://bugzilla.redhat.com/show_bug.cgi?id=1172780 (cherry picked from commit 41e6c4fac1890e4302e4bfd1aa21be362cce51f2) --- src/platform/nm-linux-platform.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c index d59b55bc1f..0c35376cdb 100644 --- a/src/platform/nm-linux-platform.c +++ b/src/platform/nm-linux-platform.c @@ -3912,6 +3912,19 @@ ip4_route_delete (NMPlatform *platform, int ifindex, in_addr_t network, int plen cache = choose_cache_by_type (platform, OBJECT_TYPE_IP4_ROUTE); + if (metric == 0) { + /* Deleting an IPv4 route with metric 0 does not only delete an exectly matching route. + * If no route with metric 0 exists, it might delete another route to the same destination. + * For nm_platform_ip4_route_delete() we don't want this semantic. + * + * Instead, re-fetch the route from kernel, and if that fails, there is nothing to do. + * On success, there is still a race that we might end up deleting the wrong route. */ + if (!refresh_object (platform, (struct nl_object *) route, FALSE, NM_PLATFORM_REASON_INTERNAL)) { + rtnl_route_put ((struct rtnl_route *) route); + return TRUE; + } + } + /* when deleting an IPv4 route, several fields of the provided route must match. * Lookup in the cache so that we hopefully get the right values. */ cached_object = (struct rtnl_route *) nl_cache_search (cache, route);