network: Allow to configure GW even UseRoutes=false

When use UseRoutes=False so the DHCP request itself does not request
for Classless Static Routes option.
As a result, the DHCP server will only respond with a Router option.
In this case since we are using the UseRoutes=False option the gateway
that comes in via the router option does not get configured.
This patch fixes theis behaviour.

1 files changed, 31 insertions, 32 deletions

diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
index 5f5a21a59f..34770f6f2b 100644
--- a/src/network/networkd-dhcp4.c
+++ b/src/network/networkd-dhcp4.c
@@ -240,9 +240,6 @@ static int link_set_dhcp_routes(Link *link) {
         if (!link->network) /* link went down while we configured the IP addresses? */
                 return 0;
 
-        if (!link->network->dhcp_use_routes)
-                return 0;
-
         if (!link_has_carrier(link) && !link->network->configure_without_carrier)
                 /* During configuring addresses, the link lost its carrier. As networkd is dropping
                  * the addresses now, let's not configure the routes either. */
@@ -290,37 +287,39 @@ static int link_set_dhcp_routes(Link *link) {
                 }
         }
 
-        for (i = 0; i < n; i++) {
-                _cleanup_(route_freep) Route *route = NULL;
-
-                /* if the DHCP server returns both a Classless Static Routes option and a Static Routes option,
-                   the DHCP client MUST ignore the Static Routes option. */
-                if (classless_route &&
-                    sd_dhcp_route_get_option(static_routes[i]) != SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE)
-                        continue;
-
-                r = route_new(&route);
-                if (r < 0)
-                        return log_link_error_errno(link, r, "Could not allocate route: %m");
-
-                route->family = AF_INET;
-                route->protocol = RTPROT_DHCP;
-                assert_se(sd_dhcp_route_get_gateway(static_routes[i], &route->gw.in) >= 0);
-                assert_se(sd_dhcp_route_get_destination(static_routes[i], &route->dst.in) >= 0);
-                assert_se(sd_dhcp_route_get_destination_prefix_length(static_routes[i], &route->dst_prefixlen) >= 0);
-                route->priority = link->network->dhcp_route_metric;
-                route->table = table;
-                route->mtu = link->network->dhcp_route_mtu;
-                route->scope = route_scope_from_address(route, &address);
-                if (IN_SET(route->scope, RT_SCOPE_LINK, RT_SCOPE_UNIVERSE))
-                        route->prefsrc.in = address;
+        if (link->network->dhcp_use_routes) {
+                for (i = 0; i < n; i++) {
+                        _cleanup_(route_freep) Route *route = NULL;
 
-                if (set_contains(link->dhcp_routes, route))
-                        continue;
+                        /* if the DHCP server returns both a Classless Static Routes option and a Static Routes option,
+                           the DHCP client MUST ignore the Static Routes option. */
+                        if (classless_route &&
+                            sd_dhcp_route_get_option(static_routes[i]) != SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE)
+                                continue;
 
-                r = dhcp_route_configure(&route, link);
-                if (r < 0)
-                        return log_link_error_errno(link, r, "Could not set route: %m");
+                        r = route_new(&route);
+                        if (r < 0)
+                                return log_link_error_errno(link, r, "Could not allocate route: %m");
+
+                        route->family = AF_INET;
+                        route->protocol = RTPROT_DHCP;
+                        assert_se(sd_dhcp_route_get_gateway(static_routes[i], &route->gw.in) >= 0);
+                        assert_se(sd_dhcp_route_get_destination(static_routes[i], &route->dst.in) >= 0);
+                        assert_se(sd_dhcp_route_get_destination_prefix_length(static_routes[i], &route->dst_prefixlen) >= 0);
+                        route->priority = link->network->dhcp_route_metric;
+                        route->table = table;
+                        route->mtu = link->network->dhcp_route_mtu;
+                        route->scope = route_scope_from_address(route, &address);
+                        if (IN_SET(route->scope, RT_SCOPE_LINK, RT_SCOPE_UNIVERSE))
+                                route->prefsrc.in = address;
+
+                        if (set_contains(link->dhcp_routes, route))
+                                continue;
+
+                        r = dhcp_route_configure(&route, link);
+                        if (r < 0)
+                                return log_link_error_errno(link, r, "Could not set route: %m");
+                }
         }
 
         r = sd_dhcp_lease_get_router(link->dhcp_lease, &router);