networkd: route - allow routes without a gateway

For IPv6, the kernel returns EINVAL if a route is added with the
RTA_GATEWAY attribute set to in6addr_any (::). A route without a
gateway is useful in some situations, such as layer 3 tunneling
(sit, gre, etc.).

This patch prevents the RTA_GATEWAY attribute from being added
when route.in_addr is ip6addr_any (::).

diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c
index 10d8cd902a8c16147eb52bb4aa0d01781054ed1b..82c9e002fdd337942dd666570f88d7826a8c4662 100644 (file)
--- a/src/network/networkd-route.c
+++ b/src/network/networkd-route.c
@@ -118,13 +118,15 @@ int route_drop(Route *route, Link *link,
                 return r;
         }
 
-        if (route->family == AF_INET)
-                r = sd_rtnl_message_append_in_addr(req, RTA_GATEWAY, &route->in_addr.in);
-        else if (route->family == AF_INET6)
-                r = sd_rtnl_message_append_in6_addr(req, RTA_GATEWAY, &route->in_addr.in6);
-        if (r < 0) {
-                log_error("Could not append RTA_GATEWAY attribute: %s", strerror(-r));
-                return r;
+        if (!in_addr_is_null(route->family, &route->in_addr)) {
+                if (route->family == AF_INET)
+                        r = sd_rtnl_message_append_in_addr(req, RTA_GATEWAY, &route->in_addr.in);
+                else if (route->family == AF_INET6)
+                        r = sd_rtnl_message_append_in6_addr(req, RTA_GATEWAY, &route->in_addr.in6);
+                if (r < 0) {
+                        log_error("Could not append RTA_GATEWAY attribute: %s", strerror(-r));
+                        return r;
+                }
         }
 
         if (route->dst_prefixlen) {
@@ -203,13 +205,15 @@ int route_configure(Route *route, Link *link,
                 return r;
         }
 
-        if (route->family == AF_INET)
-                r = sd_rtnl_message_append_in_addr(req, RTA_GATEWAY, &route->in_addr.in);
-        else if (route->family == AF_INET6)
-                r = sd_rtnl_message_append_in6_addr(req, RTA_GATEWAY, &route->in_addr.in6);
-        if (r < 0) {
-                log_error("Could not append RTA_GATEWAY attribute: %s", strerror(-r));
-                return r;
+        if (!in_addr_is_null(route->family, &route->in_addr)) {
+                if (route->family == AF_INET)
+                        r = sd_rtnl_message_append_in_addr(req, RTA_GATEWAY, &route->in_addr.in);
+                else if (route->family == AF_INET6)
+                        r = sd_rtnl_message_append_in6_addr(req, RTA_GATEWAY, &route->in_addr.in6);
+                if (r < 0) {
+                        log_error("Could not append RTA_GATEWAY attribute: %s", strerror(-r));
+                        return r;
+                }
         }
 
         if (route->dst_prefixlen) {