1 files changed, 54 insertions, 15 deletions

diff --git a/src/network/networkd-ndisc.c b/src/network/networkd-ndisc.c
index 7cafe1f..50d284b 100644
--- a/src/network/networkd-ndisc.c
+++ b/src/network/networkd-ndisc.c
@@ -222,20 +222,33 @@ static int ndisc_request_route(Route *route, Link *link) {
                 /* Note, here do not call route_remove_and_cancel() with 'route' directly, otherwise
                  * existing route(s) may be removed needlessly. */
 
-                if (route_get(link->manager, route, &existing) >= 0) {
-                        /* Found an existing route that may conflict with this route. */
+                /* First, check if a conflicting route is already requested. If there is an existing route,
+                 * and also an existing pending request, then the source may be updated by the request. So,
+                 * we first need to check the source of the requested route. */
+                if (route_get_request(link->manager, route, &req) >= 0) {
+                        existing = ASSERT_PTR(req->userdata);
                         if (!route_can_update(existing, route)) {
-                                log_link_debug(link, "Found an existing route that conflicts with new route based on a received RA, removing.");
+                                if (existing->source == NETWORK_CONFIG_SOURCE_STATIC) {
+                                        log_link_debug(link, "Found a pending route request that conflicts with new request based on a received RA, ignoring request.");
+                                        return 0;
+                                }
+
+                                log_link_debug(link, "Found a pending route request that conflicts with new request based on a received RA, cancelling.");
                                 r = route_remove_and_cancel(existing, link->manager);
                                 if (r < 0)
                                         return r;
                         }
                 }
 
-                if (route_get_request(link->manager, route, &req) >= 0) {
-                        existing = ASSERT_PTR(req->userdata);
+                /* Then, check if a conflicting route exists. */
+                if (route_get(link->manager, route, &existing) >= 0) {
                         if (!route_can_update(existing, route)) {
-                                log_link_debug(link, "Found a pending route request that conflicts with new request based on a received RA, cancelling.");
+                                if (existing->source == NETWORK_CONFIG_SOURCE_STATIC) {
+                                        log_link_debug(link, "Found an existing route that conflicts with new route based on a received RA, ignoring request.");
+                                        return 0;
+                                }
+
+                                log_link_debug(link, "Found an existing route that conflicts with new route based on a received RA, removing.");
                                 r = route_remove_and_cancel(existing, link->manager);
                                 if (r < 0)
                                         return r;
@@ -291,18 +304,44 @@ static int ndisc_remove_route(Route *route, Link *link) {
         if (r < 0)
                 return r;
 
-        if (route->pref_set) {
-                ndisc_set_route_priority(link, route);
-                return route_remove_and_cancel(route, link->manager);
-        }
-
-        uint8_t pref;
+        uint8_t pref, pref_original = route->pref;
         FOREACH_ARGUMENT(pref, SD_NDISC_PREFERENCE_LOW, SD_NDISC_PREFERENCE_MEDIUM, SD_NDISC_PREFERENCE_HIGH) {
+                Route *existing;
+                Request *req;
+
+                /* If the preference is specified by the user config (that is, for semi-static routes),
+                 * rather than RA, then only search conflicting routes that have the same preference. */
+                if (route->pref_set && pref != pref_original)
+                        continue;
+
                 route->pref = pref;
                 ndisc_set_route_priority(link, route);
-                r = route_remove_and_cancel(route, link->manager);
-                if (r < 0)
-                        return r;
+
+                /* Unfortunately, we cannot directly pass 'route' to route_remove_and_cancel() here, as the
+                 * same or similar route may be configured or requested statically. */
+
+                /* First, check if the route is already requested. If there is an existing route, and also an
+                 * existing pending request, then the source may be updated by the request. So, we first need
+                 * to check the source of the requested route. */
+                if (route_get_request(link->manager, route, &req) >= 0) {
+                        existing = ASSERT_PTR(req->userdata);
+                        if (existing->source == NETWORK_CONFIG_SOURCE_STATIC)
+                                continue;
+
+                        r = route_remove_and_cancel(existing, link->manager);
+                        if (r < 0)
+                                return r;
+                }
+
+                /* Then, check if the route exists. */
+                if (route_get(link->manager, route, &existing) >= 0) {
+                        if (existing->source == NETWORK_CONFIG_SOURCE_STATIC)
+                                continue;
+
+                        r = route_remove_and_cancel(existing, link->manager);
+                        if (r < 0)
+                                return r;
+                }
         }
 
         return 0;