gistfile0.txt

diff --git a/cloudinit/distros/bsd_utils.py b/cloudinit/distros/bsd_utils.py
index 00cd0662..a1764cae 100644
--- a/cloudinit/distros/bsd_utils.py
+++ b/cloudinit/distros/bsd_utils.py
@@ -1,5 +1,6 @@
 # This file is part of cloud-init. See LICENSE file for license information.
 
+import re
 import shlex
 
 from cloudinit import util
@@ -26,6 +27,13 @@ def get_rc_config_value(key, fn="/etc/rc.conf"):
             return _unquote(value)
 
 
+def get_rc_config_line(search, fn="/etc/rc.conf"):
+    for line in util.load_file(fn).splitlines():
+        x = re.match(search, line)
+        if x:
+            return x
+
+
 def set_rc_config_value(key, value, fn="/etc/rc.conf"):
     lines = []
     done = False
diff --git a/cloudinit/distros/networking.py b/cloudinit/distros/networking.py
index 47daf8db..c3f0122c 100644
--- a/cloudinit/distros/networking.py
+++ b/cloudinit/distros/networking.py
@@ -5,6 +5,7 @@ import re
 from typing import List, Optional
 
 from cloudinit import net, subp, util
+from cloudinit.distros import bsd_utils
 from cloudinit.distros.parsers import ifconfig
 
 LOG = logging.getLogger(__name__)
@@ -273,6 +274,17 @@ class FreeBSDNetworking(BSDNetworking):
             return True
         return False
 
+    def device_driver(self, devname: DeviceName):
+        if self.is_renamed(devname):
+            search = """ifconfig_([^_]+)_name={}""".format(devname)
+            devname = bsd_utils.get_rc_config_line(search)
+        base, _ = re.fullmatch("([a-z]+)([0-9]+).*", devname).groups()
+        # optionally, verify the driver:
+        # driver, _ = subp.subp(
+        #    ["sysctl", "-b", "dev.{}.{}.%driver".format(base, index)]
+        # )
+        return base
+
 
 class LinuxNetworking(Networking):
     """Implementation of networking functionality common to Linux distros."""