# Copyright (c) 2011, 2012 Nicira, Inc. # # 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. """ util module contains some helper function """ import array import exceptions import fcntl import os import select import socket import struct import signal import subprocess import re import xmlrpclib def str_ip(ip_address): """ Converts an IP address from binary format to a string. """ (x1, x2, x3, x4) = struct.unpack("BBBB", ip_address) return ("%u.%u.%u.%u") % (x1, x2, x3, x4) def get_interface_mtu(iface): """ Returns MTU of the given interface. """ s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) indata = iface + ('\0' * (32 - len(iface))) try: outdata = fcntl.ioctl(s.fileno(), 0x8921, indata) # socket.SIOCGIFMTU mtu = struct.unpack("16si12x", outdata)[1] except: return 0 return mtu def get_interface(address): """ Finds first interface that has given address """ bytes = 256 * 32 s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) names = array.array('B', '\0' * bytes) outbytes = struct.unpack('iL', fcntl.ioctl( s.fileno(), 0x8912, # SIOCGIFCONF struct.pack('iL', bytes, names.buffer_info()[0]) ))[0] namestr = names.tostring() for i in range(0, outbytes, 40): name = namestr[i:i + 16].split('\0', 1)[0] if address == str_ip(namestr[i + 20:i + 24]): return name return None # did not find interface we were looking for def uname(): os_info = os.uname() return os_info[2] # return only the kernel version number def start_process(args): try: p = subprocess.Popen(args, stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = subprocess.PIPE) out, err = p.communicate() return (p.returncode, out, err) except exceptions.OSError: return (-1, None, None) def get_driver(iface): ret, out, _err = start_process(["ethtool", "-i", iface]) if ret == 0: lines = out.splitlines() driver = "%s(%s)" % (lines[0], lines[1]) # driver name + version else: driver = None return driver def interface_up(iface): """ This function brings given iface up. """ ret, _out, _err = start_process(["ifconfig", iface, "up"]) return ret def interface_assign_ip(iface, ip_addr, mask): """ This function allows to assign IP address to an interface. If mask is an empty string then ifconfig will decide what kind of mask to use. The caller can also specify the mask by using CIDR notation in ip argument by leaving the mask argument as an empty string. In case of success this function returns 0. """ args = ["ifconfig", iface, ip_addr] if mask is not None: args.append("netmask") args.append(mask) ret, _out, _err = start_process(args) return ret def interface_get_ip(iface): """ This function returns tuple - ip and mask that was assigned to the interface. """ args = ["ifconfig", iface] ret, out, _err = start_process(args) if ret == 0: ip = re.search(r'inet addr:(\S+)', out) mask = re.search(r'Mask:(\S+)', out) if ip is not None and mask is not None: return (ip.group(1), mask.group(1)) else: return ret def move_routes(iface1, iface2): """ This function moves routes from iface1 to iface2. """ args = ["ip", "route", "show", "dev", iface1] ret, out, _err = start_process(args) if ret == 0: for route in out.splitlines(): args = ["ip", "route", "replace", "dev", iface2] + route.split() start_process(args) def get_interface_from_routing_decision(ip): """ This function returns the interface through which the given ip address is reachable. """ args = ["ip", "route", "get", ip] ret, out, _err = start_process(args) if ret == 0: iface = re.search(r'dev (\S+)', out) if iface: return iface.group(1) return None def rpc_client(ip, port): return xmlrpclib.Server("http://%s:%u/" % (ip, port), allow_none=True) def sigint_intercept(): """ Intercept SIGINT from child (the local ovs-test server process). """ signal.signal(signal.SIGINT, signal.SIG_IGN) def start_local_server(port): """ This function spawns an ovs-test server that listens on specified port and blocks till the spawned ovs-test server is ready to accept XML RPC connections. """ p = subprocess.Popen(["ovs-test", "-s", str(port)], stdout=subprocess.PIPE, stderr=subprocess.PIPE, preexec_fn=sigint_intercept) fcntl.fcntl( p.stdout.fileno(),fcntl.F_SETFL, fcntl.fcntl(p.stdout.fileno(), fcntl.F_GETFL) | os.O_NONBLOCK) while p.poll() is None: fd = select.select([p.stdout.fileno()], [], [])[0] if fd: out = p.stdout.readline() if out.startswith("Starting RPC server"): break if p.poll() is not None: raise RuntimeError("Couldn't start local instance of ovs-test server") return p def get_datagram_sizes(mtu1, mtu2): """ This function calculates all the "interesting" datagram sizes so that we test both - receive and send side with different packets sizes. """ s1 = set([8, mtu1 - 100, mtu1 - 28, mtu1]) s2 = set([8, mtu2 - 100, mtu2 - 28, mtu2]) return sorted(s1.union(s2)) def ip_from_cidr(string): """ This function removes the netmask (if present) from the given string and returns the IP address. """ token = string.split("/") return token[0] def bandwidth_to_string(bwidth): """Convert bandwidth from long to string and add units.""" bwidth = bwidth * 8 # Convert back to bits/second if bwidth >= 10000000: return str(int(bwidth / 1000000)) + "Mbps" elif bwidth > 10000: return str(int(bwidth / 1000)) + "Kbps" else: return str(int(bwidth)) + "bps"