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
29 def load_topology(args):
30 """Load topology file referenced to by parameter passed to this script.
32 :param args: arguments parsed from commandline
33 :type args: ArgumentParser().parse_args()
34 :return: Python representation of topology yaml
38 with open(args.topology, 'r') as stream:
40 data = yaml.load(stream)
41 except yaml.YAMLError as exc:
42 print 'Failed to load topology file: {0}'.format(args.topology)
48 def ssh_no_error(ssh, cmd):
49 """Execute a command over ssh channel, and log and exit if the command
52 :param ssh: SSH() object connected to a node
53 :param cmd: Command line to execute on remote node
54 :type ssh: SSH() object
56 :return: stdout from the SSH command
59 ret, stdo, stde = ssh.exec_command(cmd)
61 print 'Command execution failed: "{}"'.format(cmd)
62 print 'stdout: {0}'.format(stdo)
63 print 'stderr: {0}'.format(stde)
64 raise RuntimeError('Unexpected ssh command failure')
68 def update_mac_addresses_for_node(node):
69 """For given node loop over all ports with PCI address and look for its MAC
72 This function firstly unbinds the PCI device from its current driver
73 and binds it to linux kernel driver. After the device is bound to specific
74 linux kernel driver the MAC address is extracted from /sys/bus/pci location
75 and stored within the node dictionary that was passed to this function.
76 :param node: Node from topology
80 for port_name, port in node['interfaces'].items():
81 if not port.has_key('driver'):
82 err_msg = '{0} port {1} has no driver element, exiting'.format(
83 node['host'], port_name)
84 raise RuntimeError(err_msg)
89 # TODO: make following SSH commands into one-liner to save on SSH opers
91 # First unbind from current driver
92 drvr_dir_path = '/sys/bus/pci/devices/{0}/driver'.format(
96 echo {1} | sudo tee {0}/unbind ;
98 true Do not have to do anything, port already unbound ;
99 fi'''.format(drvr_dir_path, port['pci_address'])
100 ssh_no_error(ssh, cmd)
102 # Then bind to the 'driver' from topology for given port
103 cmd = 'echo {0} | sudo tee /sys/bus/pci/drivers/{1}/bind'.\
104 format(port['pci_address'], port['driver'])
105 ssh_no_error(ssh, cmd)
107 # Then extract the mac address and store it in the topology
108 cmd = 'cat /sys/bus/pci/devices/{0}/net/*/address'.format(
110 mac = ssh_no_error(ssh, cmd).strip()
111 pattern = re.compile("^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$")
112 if not pattern.match(mac):
113 raise RuntimeError('MAC address read from host {0} {1} is in '
114 'bad format "{2}"'.format(node['host'],
115 port['pci_address'], mac))
116 print '{0}: Found MAC address of PCI device {1}: {2}'.format(
117 node['host'], port['pci_address'], mac)
118 port['mac_address'] = mac
120 def update_nodes_mac_addresses(topology):
121 """Loop over nodes in topology and get mac addresses for all listed ports
122 based on PCI addresses.
124 :param topology: Topology information with nodes
129 for node in topology['nodes'].values():
130 update_mac_addresses_for_node(node)
132 def dump_updated_topology(topology, args):
133 """Writes or prints out updated topology file.
135 :param topology: Topology information with nodes
136 :param args: arguments parsed from command line
138 :type args: ArgumentParser().parse_args()
139 :return: 1 if error occured, 0 if successful
145 if os.path.isfile(args.output_file):
146 print ('File {0} already exists. If you want to overwrite this '
147 'file, add -f as a parameter to this script'.format(
150 with open(args.output_file, 'w') as stream:
151 yaml.dump(topology, stream, default_flow_style=False)
153 print yaml.dump(topology, default_flow_style=False)
158 parser = ArgumentParser()
159 parser.add_argument('topology', help="Topology yaml file to read")
160 parser.add_argument('--output-file', '-o', help='Output file')
161 parser.add_argument('-f', '--force', help='Overwrite existing file',
162 action='store_const', const=True)
163 parser.add_argument('--verbose', '-v', action='store_true')
164 args = parser.parse_args()
166 topology = load_topology(args)
167 update_nodes_mac_addresses(topology)
168 ret = dump_updated_topology(topology, args)
173 if __name__ == "__main__":