1 #!/usr/bin/env python2.7
2 # Copyright (c) 2016 Cisco and/or its affiliates.
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at:
7 # http://www.apache.org/licenses/LICENSE-2.0
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
15 """This executable python module gathers MAC address data from topology nodes.
16 It requires that all interfaces/port elements in topology have driver field.
17 This script binds the port in given node to set linux kernel driver and
18 extracts MAC address from it."""
23 from argparse import ArgumentParser
27 from resources.libraries.python.ssh import SSH
30 def load_topology(args):
31 """Load topology file referenced to by parameter passed to this script.
33 :param args: Arguments parsed from commandline.
34 :type args: ArgumentParser().parse_args()
35 :return: Python representation of topology YAML.
39 with open(args.topology, 'r') as stream:
41 data = yaml.load(stream)
42 except yaml.YAMLError as exc:
43 print 'Failed to load topology file: {0}'.format(args.topology)
50 def ssh_no_error(ssh, cmd):
51 """Execute a command over ssh channel, and log and exit if the command
54 :param ssh: SSH() object connected to a node.
55 :param cmd: Command line to execute on remote node.
56 :type ssh: SSH() object
58 :return: stdout from the SSH command.
61 ret, stdo, stde = ssh.exec_command(cmd)
63 print 'Command execution failed: "{}"'.format(cmd)
64 print 'stdout: {0}'.format(stdo)
65 print 'stderr: {0}'.format(stde)
66 raise RuntimeError('Unexpected ssh command failure')
71 def update_mac_addresses_for_node(node):
72 """For given node loop over all ports with PCI address and look for its MAC
75 This function firstly unbinds the PCI device from its current driver
76 and binds it to linux kernel driver. After the device is bound to specific
77 linux kernel driver the MAC address is extracted from /sys/bus/pci location
78 and stored within the node dictionary that was passed to this function.
80 :param node: Node from topology.
83 for port_name, port in node['interfaces'].items():
84 if 'driver' not in port:
85 err_msg = '{0} port {1} has no driver element, exiting'.format(
86 node['host'], port_name)
87 raise RuntimeError(err_msg)
92 # TODO: make following SSH commands into one-liner to save on SSH opers
94 # First unbind from current driver
95 drvr_dir_path = '/sys/bus/pci/devices/{0}/driver'.format(
99 echo {1} | sudo tee {0}/unbind ;
101 true Do not have to do anything, port already unbound ;
102 fi'''.format(drvr_dir_path, port['pci_address'])
103 ssh_no_error(ssh, cmd)
105 # Then bind to the 'driver' from topology for given port
106 cmd = 'echo {0} | sudo tee /sys/bus/pci/drivers/{1}/bind'.\
107 format(port['pci_address'], port['driver'])
108 ssh_no_error(ssh, cmd)
110 # Then extract the mac address and store it in the topology
111 cmd = 'cat /sys/bus/pci/devices/{0}/net/*/address'.format(
113 mac = ssh_no_error(ssh, cmd).strip()
114 pattern = re.compile("^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$")
115 if not pattern.match(mac):
116 raise RuntimeError('MAC address read from host {0} {1} is in '
118 .format(node['host'], port['pci_address'], mac))
119 print '{0}: Found MAC address of PCI device {1}: {2}'.format(
120 node['host'], port['pci_address'], mac)
121 port['mac_address'] = mac
124 def update_nodes_mac_addresses(topology):
125 """Loop over nodes in topology and get mac addresses for all listed ports
126 based on PCI addresses.
128 :param topology: Topology information with nodes.
131 for node in topology['nodes'].values():
132 update_mac_addresses_for_node(node)
135 def dump_updated_topology(topology, args):
136 """Writes or prints out updated topology file.
138 :param topology: Topology information with nodes.
139 :param args: Arguments parsed from command line.
141 :type args: ArgumentParser().parse_args()
142 :return: 1 if error occurred, 0 if successful.
147 if os.path.isfile(args.output_file):
148 print ('File {0} already exists. If you want to overwrite this '
149 'file, add -f as a parameter to this script'.format(
152 with open(args.output_file, 'w') as stream:
153 yaml.dump(topology, stream, default_flow_style=False)
155 print yaml.dump(topology, default_flow_style=False)
161 parser = ArgumentParser()
162 parser.add_argument('topology', help="Topology yaml file to read")
163 parser.add_argument('--output-file', '-o', help='Output file')
164 parser.add_argument('-f', '--force', help='Overwrite existing file',
165 action='store_const', const=True)
166 parser.add_argument('--verbose', '-v', action='store_true')
167 args = parser.parse_args()
169 topology = load_topology(args)
170 update_nodes_mac_addresses(topology)
171 ret = dump_updated_topology(topology, args)
176 if __name__ == "__main__":