network/route-nexthop: introduce route_nexthops_copy()

This also introduce an extra argument for route_dup(), but it is
currently unused, will be used later.

No functional change, just preparation for later commits.

src/network/networkd-dhcp4.c

@@ -659,7 +659,7 @@ static int dhcp4_request_semi_static_routes(Link *link) {
                 if (r < 0)
                         return r;
 
-                r = route_dup(rt, &route);
+                r = route_dup(rt, NULL, &route);
                 if (r < 0)
                         return r;
 

src/network/networkd-ndisc.c

@@ -340,7 +340,7 @@ static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
                 if (route_gw->nexthop.family != AF_INET6)
                         continue;
 
-                r = route_dup(route_gw, &route);
+                r = route_dup(route_gw, NULL, &route);
                 if (r < 0)
                         return r;
 

src/network/networkd-route-nexthop.c

@@ -170,6 +170,36 @@ int route_nexthops_compare_func(const Route *a, const Route *b) {
         }}
 }
 
+static int route_nexthop_copy(const RouteNextHop *src, RouteNextHop *dest) {
+        assert(src);
+        assert(dest);
+
+        *dest = *src;
+
+        /* unset pointer copied in the above. */
+        dest->ifname = NULL;
+
+        return strdup_or_null(src->ifindex == 0 ? NULL : src->ifname, &dest->ifname);
+}
+
+int route_nexthops_copy(const Route *src, const RouteNextHop *nh, Route *dest) {
+        assert(src);
+        assert(dest);
+
+        if (src->nexthop_id != 0 || route_type_is_reject(src))
+                return 0;
+
+        if (nh)
+                return route_nexthop_copy(nh, &dest->nexthop);
+
+        if (ordered_set_isempty(src->nexthops))
+                return route_nexthop_copy(&src->nexthop, &dest->nexthop);
+
+        /* Currently, this does not copy multipath routes. */
+
+        return 0;
+}
+
 int route_nexthop_get_link(Manager *manager, Link *link, const RouteNextHop *nh, Link **ret) {
         assert(manager);
         assert(nh);

src/network/networkd-route-nexthop.h

@@ -24,6 +24,8 @@ typedef struct RouteNextHop {
         /* unsupported attributes: RTA_FLOW (IPv4 only), RTA_ENCAP_TYPE, RTA_ENCAP. */
 } RouteNextHop;
 
+#define ROUTE_NEXTHOP_NULL ((const RouteNextHop) {})
+
 RouteNextHop* route_nexthop_free(RouteNextHop *nh);
 DEFINE_TRIVIAL_CLEANUP_FUNC(RouteNextHop*, route_nexthop_free);
 
@@ -32,6 +34,8 @@ void route_nexthops_done(Route *route);
 void route_nexthops_hash_func(const Route *route, struct siphash *state);
 int route_nexthops_compare_func(const Route *a, const Route *b);
 
+int route_nexthops_copy(const Route *src, const RouteNextHop *nh, Route *dest);
+
 int route_nexthop_get_link(Manager *manager, Link *link, const RouteNextHop *nh, Link **ret);
 int route_nexthops_is_ready_to_configure(const Route *route, Link *link);
 

src/network/networkd-route.c

@@ -336,12 +336,10 @@ static int route_get_link(Manager *manager, const Route *route, Link **ret) {
         return route_nexthop_get_link(manager, NULL, &route->nexthop, ret);
 }
 
-int route_dup(const Route *src, Route **ret) {
+int route_dup(const Route *src, const RouteNextHop *nh, Route **ret) {
         _cleanup_(route_freep) Route *dest = NULL;
         int r;
 
-        /* This does not copy mulipath routes. */
-
         assert(src);
         assert(ret);
 
@@ -355,10 +353,15 @@ int route_dup(const Route *src, Route **ret) {
         dest->wireguard = NULL;
         dest->section = NULL;
         dest->link = NULL;
+        dest->nexthop = ROUTE_NEXTHOP_NULL;
         dest->nexthops = NULL;
         dest->metric = ROUTE_METRIC_NULL;
         dest->expire = NULL;
 
+        r = route_nexthops_copy(src, nh, dest);
+        if (r < 0)
+                return r;
+
         r = route_metric_copy(&src->metric, &dest->metric);
         if (r < 0)
                 return r;
@@ -476,7 +479,7 @@ static int route_convert(Manager *manager, Link *link, const Route *route, Conve
                         if (r < 0)
                                 return r;
 
-                        r = route_dup(route, &c->routes[0]);
+                        r = route_dup(route, NULL, &c->routes[0]);
                         if (r < 0)
                                 return r;
 
@@ -499,7 +502,7 @@ static int route_convert(Manager *manager, Link *link, const Route *route, Conve
                         if (r < 0)
                                 return r;
 
-                        r = route_dup(route, &c->routes[i]);
+                        r = route_dup(route, NULL, &c->routes[i]);
                         if (r < 0)
                                 return r;
 
@@ -523,7 +526,7 @@ static int route_convert(Manager *manager, Link *link, const Route *route, Conve
         size_t i = 0;
         RouteNextHop *nh;
         ORDERED_SET_FOREACH(nh, route->nexthops) {
-                r = route_dup(route, &c->routes[i]);
+                r = route_dup(route, NULL, &c->routes[i]);
                 if (r < 0)
                         return r;
 
@@ -1129,7 +1132,7 @@ static int route_process_request(Request *req, Link *link, Route *route) {
                         if (route_get(link->manager, converted->links[i] ?: link, converted->routes[i], &existing) < 0) {
                                 _cleanup_(route_freep) Route *tmp = NULL;
 
-                                r = route_dup(converted->routes[i], &tmp);
+                                r = route_dup(converted->routes[i], NULL, &tmp);
                                 if (r < 0)
                                         return log_oom();
 
@@ -1215,7 +1218,7 @@ int link_request_route(
                 if (consume_object)
                         tmp = route;
                 else {
-                        r = route_dup(route, &tmp);
+                        r = route_dup(route, NULL, &tmp);
                         if (r < 0)
                                 return r;
                 }

src/network/networkd-route.h

@@ -86,7 +86,7 @@ DEFINE_SECTION_CLEANUP_FUNCTIONS(Route, route_free);
 
 int route_new(Route **ret);
 int route_new_static(Network *network, const char *filename, unsigned section_line, Route **ret);
-int route_dup(const Route *src, Route **ret);
+int route_dup(const Route *src, const RouteNextHop *nh, Route **ret);
 
 int route_configure_handler_internal(sd_netlink *rtnl, sd_netlink_message *m, Link *link, Route *route, const char *error_msg);
 int route_remove(Route *route);