krun: implement support for passt networking

.codespellrc

@@ -1,4 +1,4 @@
 [codespell]
 skip = libocispec,build-aux,contrib,*.1,.git,configure,Makefile,libtool,m4,autom4te.cache,*.m4,*.mk
 count =
-ignore-words-list = ser
+ignore-words-list = ser,passt

src/libcrun/container.c

@@ -1683,7 +1683,17 @@ container_init (void *args, char *notify_socket, int sync_socket, libcrun_error_
          This is a best effort operation, because the seccomp filter is already in place and it could
          stop some syscalls used by mark_or_close_fds_ge_than.
       */
-      ret = mark_or_close_fds_ge_than (entrypoint_args->container, entrypoint_args->context->preserve_fds + 3, true, err);
+      if (entrypoint_args->custom_handler->vtable->close_fds)
+        {
+          ret = entrypoint_args->custom_handler->vtable->close_fds (entrypoint_args->custom_handler->cookie,
+                                                                    entrypoint_args->container,
+                                                                    entrypoint_args->context->preserve_fds,
+                                                                    err);
+        }
+      else
+        {
+          ret = mark_or_close_fds_ge_than (entrypoint_args->container, entrypoint_args->context->preserve_fds + 3, true, err);
+        }
       if (UNLIKELY (ret < 0))
         crun_error_release (err);
 

src/libcrun/custom-handler.h

@@ -48,6 +48,9 @@ struct custom_handler_s
   int (*modify_oci_configuration) (void *cookie, libcrun_context_t *context,
                                    runtime_spec_schema_config_schema *def,
                                    libcrun_error_t *err);
+
+  int (*close_fds) (void *cookie, libcrun_container_t *container,
+                    int preserve_fds, libcrun_error_t *err);
 };
 
 struct custom_handler_manager_s;