1 files changed, 54 insertions, 0 deletions
diff --git a/python/vyos/qos/randomdetect.py b/python/vyos/qos/randomdetect.py
new file mode 100644
index 000000000..d7d84260f
--- /dev/null
+++ b/python/vyos/qos/randomdetect.py
@@ -0,0 +1,54 @@
+# 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 RandomDetect(QoSBase):
+    _parent = 1
+
+    # https://man7.org/linux/man-pages/man8/tc.8.html
+    def update(self, config, direction):
+
+        tmp = f'tc qdisc add dev {self._interface} root handle {self._parent}:0 dsmark indices 8 set_tc_index'
+        self._cmd(tmp)
+
+        tmp = f'tc filter add dev {self._interface} parent {self._parent}:0 protocol ip prio 1 tcindex mask 0xe0 shift 5'
+        self._cmd(tmp)
+
+        # Generalized Random Early Detection
+        handle = self._parent +1
+        tmp = f'tc qdisc add dev {self._interface} parent {self._parent}:0 handle {handle}:0 gred setup DPs 8 default 0 grio'
+        self._cmd(tmp)
+
+        bandwidth = self._rate_convert(config['bandwidth'])
+
+        # set VQ (virtual queue) parameters
+        for precedence, precedence_config in config['precedence'].items():
+            precedence = int(precedence)
+            avg_pkt = int(precedence_config['average_packet'])
+            limit = int(precedence_config['queue_limit']) * avg_pkt
+            min_val = int(precedence_config['minimum_threshold']) * avg_pkt
+            max_val = int(precedence_config['maximum_threshold']) * avg_pkt
+
+            tmp  = f'tc qdisc change dev {self._interface} handle {handle}:0 gred limit {limit} min {min_val} max {max_val} avpkt {avg_pkt} '
+
+            burst = (2 * int(precedence_config['minimum_threshold']) + int(precedence_config['maximum_threshold'])) // 3
+            probability = 1 / int(precedence_config['mark_probability'])
+            tmp += f'burst {burst} bandwidth {bandwidth} probability {probability} DP {precedence} prio {8 - precedence:x}'
+
+            self._cmd(tmp)
+
+        # call base class
+        super().update(config, direction)