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

1 files changed, 104 insertions, 0 deletions

diff --git a/python/vyos/qos/trafficshaper.py b/python/vyos/qos/trafficshaper.py
new file mode 100644
index 000000000..6d465b38e
--- /dev/null
+++ b/python/vyos/qos/trafficshaper.py
@@ -0,0 +1,104 @@
+# 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 math import ceil
+from vyos.qos.base import QoSBase
+
+# Kernel limits on quantum (bytes)
+MAXQUANTUM = 200000
+MINQUANTUM = 1000
+
+class TrafficShaper(QoSBase):
+    _parent = 1
+
+    # https://man7.org/linux/man-pages/man8/tc-htb.8.html
+    def update(self, config, direction):
+        class_id_max = 0
+        if 'class' in config:
+            tmp = list(config['class'])
+            tmp.sort()
+            class_id_max = tmp[-1]
+
+        r2q = 10
+        # bandwidth is a mandatory CLI node
+        speed = self._rate_convert(config['bandwidth'])
+        speed_bps = int(speed) // 8
+
+        # need a bigger r2q if going fast than 16 mbits/sec
+        if (speed_bps // r2q) >= MAXQUANTUM: # integer division
+            r2q = ceil(speed_bps // MAXQUANTUM)
+            print(r2q)
+        else:
+            # if there is a slow class then may need smaller value
+            if 'class' in config:
+                min_speed = speed_bps
+                for cls, cls_options in config['class'].items():
+                    # find class with the lowest bandwidth used
+                    if 'bandwidth' in cls_options:
+                        bw_bps = int(self._rate_convert(cls_options['bandwidth'])) // 8 # bandwidth in bytes per second
+                        if bw_bps < min_speed:
+                            min_speed = bw_bps
+
+                while (r2q > 1) and (min_speed // r2q) < MINQUANTUM:
+                    tmp = r2q -1
+                    if (speed_bps // tmp) >= MAXQUANTUM:
+                        break
+                    r2q = tmp
+
+
+        default_minor_id = int(class_id_max) +1
+        tmp = f'tc qdisc add dev {self._interface} root handle {self._parent:x}: htb r2q {r2q} default {default_minor_id:x}' # default is in hex
+        self._cmd(tmp)
+
+        tmp = f'tc class add dev {self._interface} parent {self._parent:x}: classid {self._parent:x}:1 htb rate {speed}'
+        self._cmd(tmp)
+
+        if 'class' in config:
+            for cls, cls_config in config['class'].items():
+                # class id is used later on and passed as hex, thus this needs to be an int
+                cls = int(cls)
+
+                # bandwidth is a mandatory CLI node
+                rate = self._rate_convert(cls_config['bandwidth'])
+                burst = cls_config['burst']
+                quantum = cls_config['codel_quantum']
+
+                tmp = f'tc class add dev {self._interface} parent {self._parent:x}:1 classid {self._parent:x}:{cls:x} htb rate {rate} burst {burst} quantum {quantum}'
+                if 'priority' in cls_config:
+                    priority = cls_config['priority']
+                    tmp += f' prio {priority}'
+                self._cmd(tmp)
+
+                tmp = f'tc qdisc add dev {self._interface} parent {self._parent:x}:{cls:x} sfq'
+                self._cmd(tmp)
+
+        if 'default' in config:
+                tmp = f'tc class add dev {self._interface} parent {self._parent:x}:1 classid {self._parent:x}:{default_minor_id:x} htb rate {rate} burst {burst} quantum {quantum}'
+                if 'priority' in config['default']:
+                    priority = config['default']['priority']
+                    tmp += f' prio {priority}'
+                self._cmd(tmp)
+
+                tmp = f'tc qdisc add dev {self._interface} parent {self._parent:x}:{default_minor_id:x} sfq'
+                self._cmd(tmp)
+
+        # call base class
+        super().update(config, direction)
+
+class TrafficShaperHFSC(TrafficShaper):
+    def update(self, config, direction):
+        # call base class
+        super().update(config, direction)
+