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.
84 for port_name, port in node['interfaces'].items():
85 if 'driver' not in port:
86 err_msg = '{0} port {1} has no driver element, exiting'.format(
87 node['host'], port_name)
88 raise RuntimeError(err_msg)
93 # TODO: make following SSH commands into one-liner to save on SSH opers
95 # First unbind from current driver
96 drvr_dir_path = '/sys/bus/pci/devices/{0}/driver'.format(
100 echo {1} | sudo tee {0}/unbind ;
102 true Do not have to do anything, port already unbound ;
103 fi'''.format(drvr_dir_path, port['pci_address'])
104 ssh_no_error(ssh, cmd)
106 # Then bind to the 'driver' from topology for given port
107 cmd = 'echo {0} | sudo tee /sys/bus/pci/drivers/{1}/bind'.\
108 format(port['pci_address'], port['driver'])
109 ssh_no_error(ssh, cmd)
111 # Then extract the mac address and store it in the topology
112 cmd = 'cat /sys/bus/pci/devices/{0}/net/*/address'.format(
114 mac = ssh_no_error(ssh, cmd).strip()
115 pattern = re.compile("^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$")
116 if not pattern.match(mac):
117 raise RuntimeError('MAC address read from host {0} {1} is in '
119 .format(node['host'], port['pci_address'], mac))
120 print '{0}: Found MAC address of PCI device {1}: {2}'.format(
121 node['host'], port['pci_address'], mac)
122 port['mac_address'] = mac
125 def update_nodes_mac_addresses(topology):
126 """Loop over nodes in topology and get mac addresses for all listed ports
127 based on PCI addresses.
129 :param topology: Topology information with nodes.
133 for node in topology['nodes'].values():
134 update_mac_addresses_for_node(node)
137 def dump_updated_topology(topology, args):
138 """Writes or prints out updated topology file.
140 :param topology: Topology information with nodes.
141 :param args: Arguments parsed from command line.
143 :type args: ArgumentParser().parse_args()
144 :return: 1 if error occurred, 0 if successful.
149 if os.path.isfile(args.output_file):
150 print ('File {0} already exists. If you want to overwrite this '
151 'file, add -f as a parameter to this script'.format(
154 with open(args.output_file, 'w') as stream:
155 yaml.dump(topology, stream, default_flow_style=False)
157 print yaml.dump(topology, default_flow_style=False)
163 parser = ArgumentParser()
164 parser.add_argument('topology', help="Topology yaml file to read")
165 parser.add_argument('--output-file', '-o', help='Output file')
166 parser.add_argument('-f', '--force', help='Overwrite existing file',
167 action='store_const', const=True)
168 parser.add_argument('--verbose', '-v', action='store_true')
169 args = parser.parse_args()
171 topology = load_topology(args)
172 update_nodes_mac_addresses(topology)
173 ret = dump_updated_topology(topology, args)
178 if __name__ == "__main__":