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

1 files changed, 276 insertions, 0 deletions

diff --git a/python/vyos/qos/base.py b/python/vyos/qos/base.py
new file mode 100644
index 000000000..d039bbb0f
--- /dev/null
+++ b/python/vyos/qos/base.py
@@ -0,0 +1,276 @@
+# 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.base import Warning
+from vyos.util import cmd
+from vyos.util import dict_search
+from vyos.util import read_file
+
+class QoSBase:
+    _debug = True
+    _direction = ['egress']
+    _parent = 0xffff
+
+    def __init__(self, interface):
+        self._interface = interface
+
+    def _cmd(self, command):
+        if self._debug:
+            print(f'DEBUG/QoS: {command}')
+        return cmd(command)
+
+    def get_direction(self) -> list:
+        return self._direction
+
+    def _get_class_max_id(self, config) -> int:
+        if 'class' in config:
+            tmp = list(config['class'].keys())
+            tmp.sort(key=lambda ii: int(ii))
+            return tmp[-1]
+        return None
+
+    def _tmp_qdisc(self, config : dict, cls_id : int):
+        """
+        Add/replace qdisc for every class (also default is a class). This is
+        a genetic method which need an implementation "per" queue-type.
+
+        This matches the old mapping as defined in Perl here:
+        https://github.com/vyos/vyatta-cfg-qos/blob/equuleus/lib/Vyatta/Qos/ShaperClass.pm#L223-L229
+        """
+        queue_type = dict_search('queue_type', config)
+        default_tc = f'tc qdisc replace dev {self._interface} parent {self._parent}:{cls_id:x}'
+
+        if queue_type == 'priority':
+            handle = 0x4000 + cls_id
+            default_tc += f' handle {handle:x}: prio'
+            self._cmd(default_tc)
+
+            queue_limit = dict_search('queue_limit', config)
+            for ii in range(1, 4):
+                tmp = f'tc qdisc replace dev {self._interface} parent {handle:x}:{ii:x} pfifo limit {queue_limit}'
+                self._cmd(tmp)
+
+        elif queue_type == 'fair-queue':
+            default_tc += f' sfq'
+
+            tmp = dict_search('queue_limit', config)
+            if tmp: default_tc += f' limit {tmp}'
+
+            self._cmd(default_tc)
+
+        elif queue_type == 'fq-codel':
+            default_tc += f' fq_codel'
+            tmp = dict_search('codel_quantum', config)
+            if tmp: default_tc += f' quantum {tmp}'
+
+            tmp = dict_search('flows', config)
+            if tmp: default_tc += f' flows {tmp}'
+
+            tmp = dict_search('interval', config)
+            if tmp: default_tc += f' interval {tmp}'
+
+            tmp = dict_search('interval', config)
+            if tmp: default_tc += f' interval {tmp}'
+
+            tmp = dict_search('queue_limit', config)
+            if tmp: default_tc += f' limit {tmp}'
+
+            tmp = dict_search('target', config)
+            if tmp: default_tc += f' target {tmp}'
+
+            default_tc += f' noecn'
+
+            self._cmd(default_tc)
+
+        elif queue_type == 'random-detect':
+            default_tc += f' red'
+
+            self._cmd(default_tc)
+
+        elif queue_type == 'drop-tail':
+            default_tc += f' pfifo'
+
+            tmp = dict_search('queue_limit', config)
+            if tmp: default_tc += f' limit {tmp}'
+
+            self._cmd(default_tc)
+
+    def _rate_convert(self, rate) -> int:
+        rates = {
+            'bit'   : 1,
+            'kbit'  : 1000,
+            'mbit'  : 1000000,
+            'gbit'  : 1000000000,
+            'tbit'  : 1000000000000,
+        }
+
+        if rate == 'auto':
+            speed = read_file(f'/sys/class/net/{self._interface}/speed')
+            if not speed.isnumeric():
+                Warning('Interface speed cannot be determined (assuming 10 Mbit/s)')
+                speed = 10
+            return int(speed) *1000000 # convert to MBit/s
+
+        rate_numeric = int(''.join([n for n in rate if n.isdigit()]))
+        rate_scale   = ''.join([n for n in rate if not n.isdigit()])
+
+        if int(rate_numeric) <= 0:
+            raise ValueError(f'{rate_numeric} is not a valid bandwidth <= 0')
+
+        if rate_scale:
+            return int(rate_numeric * rates[rate_scale])
+        else:
+            # No suffix implies Kbps just as Cisco IOS
+            return int(rate_numeric * 1000)
+
+    def update(self, config, direction, priority=None):
+        """ method must be called from derived class after it has completed qdisc setup """
+
+        if 'class' in config:
+            for cls, cls_config in config['class'].items():
+
+                self._tmp_qdisc(cls_config, int(cls))
+
+                if 'match' in cls_config:
+                    for match, match_config in cls_config['match'].items():
+                        for af in ['ip', 'ipv6']:
+                            # every match criteria has it's tc instance
+                            filter_cmd = f'tc filter replace dev {self._interface} parent {self._parent:x}:'
+
+                            if priority:
+                                filter_cmd += f' prio {cls}'
+                            elif 'priority' in cls_config:
+                                prio = cls_config['priority']
+                                filter_cmd += f' prio {prio}'
+
+                            filter_cmd += ' protocol all u32'
+
+                            tc_af = af
+                            if af == 'ipv6':
+                                tc_af = 'ip6'
+
+                            if af in match_config:
+                                tmp = dict_search(f'{af}.source.address', match_config)
+                                if tmp: filter_cmd += f' match {tc_af} src {tmp}'
+
+                                tmp = dict_search(f'{af}.source.port', match_config)
+                                if tmp: filter_cmd += f' match {tc_af} sport {tmp} 0xffff'
+
+                                tmp = dict_search(f'{af}.destination.address', match_config)
+                                if tmp: filter_cmd += f' match {tc_af} dst {tmp}'
+
+                                tmp = dict_search(f'{af}.destination.port', match_config)
+                                if tmp: filter_cmd += f' match {tc_af} dport {tmp} 0xffff'
+
+                                tmp = dict_search(f'{af}.protocol', match_config)
+                                if tmp: filter_cmd += f' match {tc_af} protocol {tmp} 0xff'
+
+                                # Will match against total length of an IPv4 packet and
+                                # payload length of an IPv6 packet.
+                                #
+                                # IPv4 : match u16 0x0000 ~MAXLEN at 2
+                                # IPv6 : match u16 0x0000 ~MAXLEN at 4
+                                tmp = dict_search(f'{af}.max_length', match_config)
+                                if tmp:
+                                    # We need the 16 bit two's complement of the maximum
+                                    # packet length
+                                    tmp = hex(0xffff & ~int(tmp))
+
+                                    if af == 'ip':
+                                        filter_cmd += f' match u16 0x0000 {tmp} at 2'
+                                    elif af == 'ipv6':
+                                        filter_cmd += f' match u16 0x0000 {tmp} at 4'
+
+                                # We match against specific TCP flags - we assume the IPv4
+                                # header length is 20 bytes and assume the IPv6 packet is
+                                # not using extension headers (hence a ip header length of 40 bytes)
+                                # TCP Flags are set on byte 13 of the TCP header.
+                                # IPv4 : match u8 X X at 33
+                                # IPv6 : match u8 X X at 53
+                                # with X = 0x02 for SYN and X = 0x10 for ACK
+                                tmp = dict_search(f'{af}.tcp', match_config)
+                                if tmp:
+                                    mask = 0
+                                    if 'ack' in tmp:
+                                        mask |= 0x10
+                                    if 'syn' in tmp:
+                                        mask |= 0x02
+                                    mask = hex(mask)
+
+                                    if af == 'ip':
+                                        filter_cmd += f' match u8 {mask} {mask} at 33'
+                                    elif af == 'ipv6':
+                                        filter_cmd += f' match u8 {mask} {mask} at 53'
+
+                                # The police block allows limiting of the byte or packet rate of
+                                # traffic matched by the filter it is attached to.
+                                # https://man7.org/linux/man-pages/man8/tc-police.8.html
+                                if any(tmp in ['exceed', 'bandwidth', 'burst'] for tmp in cls_config):
+                                    filter_cmd += f' action police'
+
+                                if 'exceed' in cls_config:
+                                    action = cls_config['exceed']
+                                    filter_cmd += f' conform-exceed {action}'
+                                    if 'not_exceed' in cls_config:
+                                        action = cls_config['not_exceed']
+                                        filter_cmd += f'/{action}'
+
+                                if 'bandwidth' in cls_config:
+                                    rate = self._rate_convert(cls_config['bandwidth'])
+                                    filter_cmd += f' rate {rate}'
+
+                                if 'burst' in cls_config:
+                                    burst = cls_config['burst']
+                                    filter_cmd += f' burst {burst}'
+
+                                cls = int(cls)
+                                filter_cmd += f' flowid {self._parent:x}:{cls:x}'
+                                self._cmd(filter_cmd)
+
+        if 'default' in config:
+            class_id_max = self._get_class_max_id(config)
+            default_cls_id = int(class_id_max) +1
+
+            if 'default' in config:
+                self._tmp_qdisc(config['default'], default_cls_id)
+
+            filter_cmd = f'tc filter replace dev {self._interface} parent {self._parent:x}: '
+            filter_cmd += 'prio 255 protocol all basic'
+
+            # The police block allows limiting of the byte or packet rate of
+            # traffic matched by the filter it is attached to.
+            # https://man7.org/linux/man-pages/man8/tc-police.8.html
+            if any(tmp in ['exceed', 'bandwidth', 'burst'] for tmp in cls_config):
+                filter_cmd += f' action police'
+
+            if 'exceed' in cls_config:
+                action = cls_config['exceed']
+                filter_cmd += f' conform-exceed {action}'
+                if 'not_exceed' in cls_config:
+                    action = cls_config['not_exceed']
+                    filter_cmd += f'/{action}'
+
+            if 'bandwidth' in cls_config:
+                rate = self._rate_convert(cls_config['bandwidth'])
+                filter_cmd += f' rate {rate}'
+
+            if 'burst' in cls_config:
+                burst = cls_config['burst']
+                filter_cmd += f' burst {burst}'
+
+
+            filter_cmd += f' flowid {self._parent:x}:{default_cls_id:x}'
+            self._cmd(filter_cmd)
+