Restart instances with duplicate server names to preserve all endpoints

src/utun_instance.c

@@ -1031,6 +1031,16 @@ static int instance_servers_equal(const struct CFG_SERVER* a, const struct CFG_S
     return !a && !b;
 }
 
+/* Parser сохраняет повторные server-секции отдельно; для них поимённый partial reload неоднозначен. */
+static int instance_server_names_unique(const struct CFG_SERVER* servers) {
+    for (const struct CFG_SERVER* a = servers; a; a = a->next)
+        for (const struct CFG_SERVER* b = a->next; b; b = b->next)
+            if (!strcmp(a->name, b->name)) {
+                DEBUG_WARN(DEBUG_CATEGORY_CONFIG, "duplicate server name '%s': reload requires full restart", a->name); return 0;
+            }
+    return 1;
+}
+
 static int instance_routes_equal(const struct CFG_ROUTE_ENTRY* a, const struct CFG_ROUTE_ENTRY* b) {
     while (a && b) {
         if (a->netmask != b->netmask || a->ip.family != b->ip.family ||
@@ -1098,6 +1108,7 @@ struct UTUN_INSTANCE* utun_instance_reload(struct UTUN_INSTANCE* instance, struc
     struct utun_config* previous = instance->config;
     int servers_changed = !instance_servers_equal(previous->servers, next->servers);
     int full = !instance_globals_equal(&previous->global, &next->global) ||
+        !instance_server_names_unique(previous->servers) || !instance_server_names_unique(next->servers) ||
         !instance_routes_equal(previous->route_subnets, next->route_subnets) ||
         !instance_routes_equal(previous->my_subnets, next->my_subnets) ||
         (next->global.auto_sockets != CFG_AUTO_SOCKETS_OFF && servers_changed);

tests/test_instance_contract.c

@@ -149,6 +149,12 @@ static void test_reload(struct UASYNC* ua) {
     write_config(path, "same", one, "");
     assert(utun_instance_reload(inst, ua, path) == inst && endpoint_count(inst) == 1);
     assert(!endpoint(inst, "tcp")->is_tcp && !stcp_server_list_count(inst));
+    const char* duplicates = "[server:shared]\naddr=127.0.0.1:0\ntype=private\n"
+        "[server:shared]\naddr=127.0.0.1:0\ntype=private\n";
+    write_config(path, "same", duplicates, "");
+    inst = utun_instance_reload(inst, ua, path); assert(inst && inst->core_started && endpoint_count(inst) == 2);
+    write_config(path, "same", one, "");
+    inst = utun_instance_reload(inst, ua, path); assert(inst && inst->core_started && endpoint_count(inst) == 1);
     sqlite3_stmt* statement = NULL;
     assert(sqlite3_prepare_v2(inst->topo_sqlite_db, "SELECT 1", -1, &statement, NULL) == SQLITE_OK);
     utun_instance_stop(inst); assert(!inst->running);