sonic-buildimage/files/scripts/mark_dhcp_packet.py
trzhang-msft 689c101095
update DHCP_PACKET_MARK schema (#9077)
- update DHCP_PACKET_MARK schema in state_db
- this is an update over PR: Add service mark_dhcp_packet to mux container #9015
2021-11-02 15:55:50 -07:00

109 lines
3.1 KiB
Python

#!/usr/bin/env python3
import os
import subprocess
import sys
import time
from sonic_py_common import logger
from swsscommon import swsscommon
log = logger.Logger('mark_dhcp_packet')
class MarkDhcpPacket(object):
"""
Class used to configure dhcp packet mark in ebtables
"""
def __init__(self):
self.config_db_connector = None
self.state_db_connector = None
@property
def config_db(self):
"""
Returns config DB connector.
Initializes the connector during the first call
"""
if self.config_db_connector is None:
self.config_db_connector = swsscommon.ConfigDBConnector()
self.config_db_connector.connect()
return self.config_db_connector
@property
def state_db(self):
"""
Returns the state DB connector.
Initializes the connector during the first call
"""
if self.state_db_connector is None:
self.state_db_connector = swsscommon.SonicV2Connector(host='127.0.0.1')
self.state_db_connector.connect(self.state_db_connector.STATE_DB)
return self.state_db_connector
@property
def is_dualtor(self):
"""
Checks if script is running on a dual ToR system
"""
localhost_key = self.config_db.get_keys('DEVICE_METADATA')[0]
metadata = self.config_db.get_entry('DEVICE_METADATA', localhost_key)
return 'subtype' in metadata and 'dualtor' in metadata['subtype'].lower()
def get_mux_intfs(self):
"""
Returns a list of mux cable interfaces
"""
mux_cables = self.config_db.get_table('MUX_CABLE')
mux_intfs = [intf for intf in mux_cables]
return mux_intfs
def generate_mark_from_index(self, index):
'''
type: string, format: hexadecimal
Example: 0x67001, 0x67002, ...
'''
intf_mark = "0x67" + str(index).zfill(3)
return intf_mark
def run_command(self, cmd):
subprocess.call(cmd, shell=True)
log.log_info("run command: {}".format(cmd))
def clear_dhcp_packet_marks(self):
'''
Flush the INPUT chain in ebtables upon restart
'''
self.run_command("sudo ebtables -F INPUT")
def apply_mark_in_ebtables(self, intf, mark):
self.run_command("sudo ebtables -A INPUT -i {} -j mark --mark-set {}".format(intf, mark))
def update_mark_in_state_db(self, intf, mark):
self.state_db.set(self.state_db.STATE_DB, 'DHCP_PACKET_MARK|' + intf, 'mark', mark)
def apply_marks(self):
"""
Writes dhcp packet marks in ebtables
"""
if not self.is_dualtor:
return
self.clear_dhcp_packet_marks()
for (index, intf) in enumerate(self.get_mux_intfs(), 1):
mark = self.generate_mark_from_index(index)
self.apply_mark_in_ebtables(intf, mark)
self.update_mark_in_state_db(intf, mark)
log.log_info("Finish marking dhcp packets in ebtables.")
if __name__ == '__main__':
mark_dhcp_packet = MarkDhcpPacket()
mark_dhcp_packet.apply_marks()