network/route-nexthop: split out route_nexthops_to_string()

And reorder elements shown in the debugging log.
No effective functionality changed, just refactoring.

src/network/networkd-route-nexthop.c

@@ -12,6 +12,72 @@
 #include "parse-util.h"
 #include "string-util.h"
 
+int route_nexthops_to_string(const Route *route, char **ret) {
+        _cleanup_free_ char *buf = NULL;
+        int r;
+
+        assert(route);
+        assert(ret);
+
+        if (route->nexthop_id != 0) {
+                if (asprintf(&buf, "nexthop: %"PRIu32, route->nexthop_id) < 0)
+                        return -ENOMEM;
+
+                *ret = TAKE_PTR(buf);
+                return 0;
+        }
+
+        if (route_type_is_reject(route)) {
+                buf = strdup("gw: n/a");
+                if (!buf)
+                        return -ENOMEM;
+
+                *ret = TAKE_PTR(buf);
+                return 0;
+        }
+
+        if (ordered_set_isempty(route->multipath_routes)) {
+                if (in_addr_is_set(route->gw_family, &route->gw))
+                        buf = strjoin("gw: ", IN_ADDR_TO_STRING(route->gw_family, &route->gw));
+                else if (route->gateway_from_dhcp_or_ra) {
+                        if (route->gw_family == AF_INET)
+                                buf = strdup("gw: _dhcp4");
+                        else if (route->gw_family == AF_INET6)
+                                buf = strdup("gw: _ipv6ra");
+                        else
+                                buf = strdup("gw: _dhcp");
+                } else
+                        buf = strdup("gw: n/a");
+                if (!buf)
+                        return -ENOMEM;
+
+                *ret = TAKE_PTR(buf);
+                return 0;
+        }
+
+        MultipathRoute *m;
+        ORDERED_SET_FOREACH(m, route->multipath_routes) {
+                union in_addr_union a = m->gateway.address;
+                const char *s = in_addr_is_set(m->gateway.family, &a) ? IN_ADDR_TO_STRING(m->gateway.family, &a) : NULL;
+
+                if (m->ifindex > 0)
+                        r = strextendf_with_separator(&buf, ",", "%s@%i:%"PRIu32, strempty(s), m->ifindex, m->weight + 1);
+                else if (m->ifname)
+                        r = strextendf_with_separator(&buf, ",", "%s@%s:%"PRIu32, strempty(s), m->ifname, m->weight + 1);
+                else
+                        r = strextendf_with_separator(&buf, ",", "%s:%"PRIu32, strempty(s), m->weight + 1);
+                if (r < 0)
+                        return r;
+        }
+
+        char *p = strjoin("gw: ", strna(buf));
+        if (!p)
+                return -ENOMEM;
+
+        *ret = p;
+        return 0;
+}
+
 static int append_nexthop_one(Link *link, const Route *route, const MultipathRoute *m, struct rtattr **rta, size_t offset) {
         struct rtnexthop *rtnh;
         struct rtattr *new_rta;

src/network/networkd-route-nexthop.h

@@ -5,6 +5,8 @@
 
 typedef struct Route Route;
 
+int route_nexthops_to_string(const Route *route, char **ret);
+
 int route_nexthops_set_netlink_message(Link *link, const Route *route, sd_netlink_message *message);
 int route_nexthops_read_netlink_message(Route *route, sd_netlink_message *message);
 

src/network/networkd-route.c

@@ -529,9 +529,9 @@ void link_mark_routes(Link *link, NetworkConfigSource source) {
 }
 
 static void log_route_debug(const Route *route, const char *str, const Link *link, const Manager *manager) {
-        _cleanup_free_ char *state = NULL, *gw_alloc = NULL, *prefsrc = NULL,
+        _cleanup_free_ char *state = NULL, *nexthop = NULL, *prefsrc = NULL,
                 *table = NULL, *scope = NULL, *proto = NULL, *flags = NULL;
-        const char *gw = NULL, *dst, *src;
+        const char *dst, *src;
 
         assert(route);
         assert(str);
@@ -549,32 +549,8 @@ static void log_route_debug(const Route *route, const char *str, const Link *lin
         src = in_addr_is_set(route->family, &route->src) || route->src_prefixlen > 0 ?
                 IN_ADDR_PREFIX_TO_STRING(route->family, &route->src, route->src_prefixlen) : NULL;
 
-        if (in_addr_is_set(route->gw_family, &route->gw)) {
-                (void) in_addr_to_string(route->gw_family, &route->gw, &gw_alloc);
-                gw = gw_alloc;
-        } else if (route->gateway_from_dhcp_or_ra) {
-                if (route->gw_family == AF_INET)
-                        gw = "_dhcp4";
-                else if (route->gw_family == AF_INET6)
-                        gw = "_ipv6ra";
-        } else {
-                MultipathRoute *m;
+        (void) route_nexthops_to_string(route, &nexthop);
 
-                ORDERED_SET_FOREACH(m, route->multipath_routes) {
-                        _cleanup_free_ char *buf = NULL;
-                        union in_addr_union a = m->gateway.address;
-
-                        (void) in_addr_to_string(m->gateway.family, &a, &buf);
-                        (void) strextend_with_separator(&gw_alloc, ",", strna(buf));
-                        if (m->ifname)
-                                (void) strextend(&gw_alloc, "@", m->ifname);
-                        else if (m->ifindex > 0)
-                                (void) strextendf(&gw_alloc, "@%i", m->ifindex);
-                        /* See comments in config_parse_multipath_route(). */
-                        (void) strextendf(&gw_alloc, ":%"PRIu32, m->weight + 1);
-                }
-                gw = gw_alloc;
-        }
         if (in_addr_is_set(route->family, &route->prefsrc))
                 (void) in_addr_to_string(route->family, &route->prefsrc, &prefsrc);
         (void) route_scope_to_string_alloc(route->scope, &scope);
@@ -583,13 +559,13 @@ static void log_route_debug(const Route *route, const char *str, const Link *lin
         (void) route_flags_to_string_alloc(route->flags, &flags);
 
         log_link_debug(link,
-                       "%s %s route (%s): dst: %s, src: %s, gw: %s, prefsrc: %s, scope: %s, table: %s, "
-                       "proto: %s, type: %s, nexthop: %"PRIu32", priority: %"PRIu32", flags: %s",
+                       "%s %s route (%s): dst: %s, src: %s, %s, prefsrc: %s, "
+                       "table: %s, priority: %"PRIu32", "
+                       "proto: %s, scope: %s, type: %s, flags: %s",
                        str, strna(network_config_source_to_string(route->source)), strna(state),
-                       strna(dst), strna(src), strna(gw), strna(prefsrc),
-                       strna(scope), strna(table), strna(proto),
-                       strna(route_type_to_string(route->type)),
-                       route->nexthop_id, route->priority, strna(flags));
+                       strna(dst), strna(src), strna(nexthop), strna(prefsrc),
+                       strna(table), route->priority,
+                       strna(proto), strna(scope), strna(route_type_to_string(route->type)), strna(flags));
 }
 
 static int route_set_netlink_message(const Route *route, sd_netlink_message *req, Link *link) {