udev: add new builtin net_driver

Currently the ID_NET_DRIVER is set in net_setup_link builtin.
But this is called pretty late in the udev processing chain.

Right now in some custom rules it was workarounded by calling ethtool
binary directly, which is ugly.

So let's split this code to a separate builtin.

1 files changed, 43 insertions, 0 deletions

diff --git a/src/udev/udev-builtin-net_driver.c b/src/udev/udev-builtin-net_driver.c
new file mode 100644
index 0000000000..f1642a491d
--- /dev/null
+++ b/src/udev/udev-builtin-net_driver.c
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "device-util.h"
+#include "errno-util.h"
+#include "ethtool-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "string-util.h"
+#include "udev-builtin.h"
+
+static int builtin_net_driver_set_driver(UdevEvent *event, int argc, char **argv, bool test) {
+        sd_device *dev = ASSERT_PTR(ASSERT_PTR(event)->dev);
+        _cleanup_close_ int ethtool_fd = -EBADF;
+        _cleanup_free_ char *driver = NULL;
+        const char *sysname;
+        int r;
+
+        r = sd_device_get_sysname(dev, &sysname);
+        if (r < 0)
+                return log_device_warning_errno(dev, r, "Failed to get sysname: %m");
+
+        r = ethtool_get_driver(&ethtool_fd, sysname, &driver);
+        if (ERRNO_IS_NEG_NOT_SUPPORTED(r)) {
+                log_device_debug_errno(dev, r, "Querying driver name via ethtool API is not supported by device '%s', ignoring: %m", sysname);
+                return 0;
+        }
+        if (r == -ENODEV) {
+                log_device_debug_errno(dev, r, "Device already vanished, ignoring.");
+                return 0;
+        }
+        if (r < 0)
+                return log_device_warning_errno(dev, r, "Failed to get driver for '%s': %m", sysname);
+
+        return udev_builtin_add_property(event->dev, test, "ID_NET_DRIVER", driver);
+}
+
+const UdevBuiltin udev_builtin_net_driver = {
+        .name = "net_driver",
+        .cmd = builtin_net_driver_set_driver,
+        .help = "Set driver for network device",
+        .run_once = true,
+};