+#!/usr/bin/env python2.7
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""This executable python module gathers MAC address data from topology nodes.
+It requires that all interfaces/port elements in topology have driver field.
+This script binds the port in given node to set linux kernel driver and
+extracts MAC address from it."""
+
+import sys
+import os
+import re
+from argparse import ArgumentParser
+
+import yaml
+
+from resources.libraries.python.ssh import SSH
+
+def load_topology(args):
+ """Load topology file referenced to by parameter passed to this script.
+
+ :param args: arguments parsed from commandline
+ :type args: ArgumentParser().parse_args()
+ :return: Python representation of topology yaml
+ :rtype: dict
+ """
+ data = None
+ with open(args.topology, 'r') as stream:
+ try:
+ data = yaml.load(stream)
+ except yaml.YAMLError as exc:
+ print 'Failed to load topology file: {0}'.format(args.topology)
+ print exc
+ raise
+
+ return data
+
+def ssh_no_error(ssh, cmd):
+ """Execute a command over ssh channel, and log and exit if the command
+ fials.
+
+ :param ssh: SSH() object connected to a node
+ :param cmd: Command line to execute on remote node
+ :type ssh: SSH() object
+ :type cmd: str
+ :return: stdout from the SSH command
+ :rtype: str
+ """
+ ret, stdo, stde = ssh.exec_command(cmd)
+ if 0 != ret:
+ print 'Command execution failed: "{}"'.format(cmd)
+ print 'stdout: {0}'.format(stdo)
+ print 'stderr: {0}'.format(stde)
+ raise RuntimeError('Unexpected ssh command failure')
+
+ return stdo
+
+def update_mac_addresses_for_node(node):
+ """For given node loop over all ports with PCI address and look for its MAC
+ address.
+
+ This function firstly unbinds the PCI device from its current driver
+ and binds it to linux kernel driver. After the device is bound to specific
+ linux kernel driver the MAC address is extracted from /sys/bus/pci location
+ and stored within the node dictionary that was passed to this function.
+ :param node: Node from topology
+ :type node: dict
+ :return: None
+ """
+ for port_name, port in node['interfaces'].items():
+ if not port.has_key('driver'):
+ err_msg = '{0} port {1} has no driver element, exiting'.format(
+ node['host'], port_name)
+ raise RuntimeError(err_msg)
+
+ ssh = SSH()
+ ssh.connect(node)
+
+ # TODO: make following SSH commands into one-liner to save on SSH opers
+
+ # First unbind from current driver
+ drvr_dir_path = '/sys/bus/pci/devices/{0}/driver'.format(
+ port['pci_address'])
+ cmd = '''\
+ if [ -d {0} ]; then
+ echo {1} | sudo tee {0}/unbind ;
+ else
+ true Do not have to do anything, port already unbound ;
+ fi'''.format(drvr_dir_path, port['pci_address'])
+ ssh_no_error(ssh, cmd)
+
+ # Then bind to the 'driver' from topology for given port
+ cmd = 'echo {0} | sudo tee /sys/bus/pci/drivers/{1}/bind'.\
+ format(port['pci_address'], port['driver'])
+ ssh_no_error(ssh, cmd)
+
+ # Then extract the mac address and store it in the topology
+ cmd = 'cat /sys/bus/pci/devices/{0}/net/*/address'.format(
+ port['pci_address'])
+ mac = ssh_no_error(ssh, cmd).strip()
+ pattern = re.compile("^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$")
+ if not pattern.match(mac):
+ raise RuntimeError('MAC address read from host {0} {1} is in '
+ 'bad format "{2}"'.format(node['host'],
+ port['pci_address'], mac))
+ print '{0}: Found MAC address of PCI device {1}: {2}'.format(
+ node['host'], port['pci_address'], mac)
+ port['mac_address'] = mac
+
+def update_nodes_mac_addresses(topology):
+ """Loop over nodes in topology and get mac addresses for all listed ports
+ based on PCI addresses.
+
+ :param topology: Topology information with nodes
+ :type topology: dict
+ :return: None
+ """
+
+ for node in topology['nodes'].values():
+ update_mac_addresses_for_node(node)
+
+def dump_updated_topology(topology, args):
+ """Writes or prints out updated topology file.
+
+ :param topology: Topology information with nodes
+ :param args: arguments parsed from command line
+ :type topology: dict
+ :type args: ArgumentParser().parse_args()
+ :return: 1 if error occured, 0 if successful
+ :rtype: int
+ """
+
+ if args.output_file:
+ if not args.force:
+ if os.path.isfile(args.output_file):
+ print ('File {0} already exists. If you want to overwrite this '
+ 'file, add -f as a parameter to this script'.format(
+ args.output_file))
+ return 1
+ with open(args.output_file, 'w') as stream:
+ yaml.dump(topology, stream, default_flow_style=False)
+ else:
+ print yaml.dump(topology, default_flow_style=False)
+ return 0
+
+def main():
+ """Main function"""
+ parser = ArgumentParser()
+ parser.add_argument('topology', help="Topology yaml file to read")
+ parser.add_argument('--output-file', '-o', help='Output file')
+ parser.add_argument('-f', '--force', help='Overwrite existing file',
+ action='store_const', const=True)
+ parser.add_argument('--verbose', '-v', action='store_true')
+ args = parser.parse_args()
+
+ topology = load_topology(args)
+ update_nodes_mac_addresses(topology)
+ ret = dump_updated_topology(topology, args)
+
+ return ret
+
+
+if __name__ == "__main__":
+ sys.exit(main())
+
+
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