qos: T4284: first implementation introducing a new vyos.qos module

1 files changed, 28 insertions, 0 deletions

diff --git a/python/vyos/qos/droptail.py b/python/vyos/qos/droptail.py
new file mode 100644
index 000000000..427d43d19
--- /dev/null
+++ b/python/vyos/qos/droptail.py
@@ -0,0 +1,28 @@
+# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+from vyos.qos.base import QoSBase
+
+class DropTail(QoSBase):
+    # https://man7.org/linux/man-pages/man8/tc-pfifo.8.html
+    def update(self, config, direction):
+        tmp = f'tc qdisc add dev {self._interface} root pfifo'
+        if 'queue_limit' in config:
+            limit = config["queue_limit"]
+            tmp += f' limit {limit}'
+        self._cmd(tmp)
+
+        # call base class
+        super().update(config, direction)