import os import subprocess import pyroute2 from pyroute2 import IPRoute, NetNS, IPDB, NSPopen class Simulation(object): """ Helper class for controlling multiple namespaces. Inherit from this class and setup your namespaces. """ def __init__(self, ipdb): self.ipdb = ipdb self.ipdbs = {} self.namespaces = [] self.processes = [] self.released = False # helper function to add additional ifc to namespace # if called directly outside Simulation class, "ifc_base_name" should be # different from "name", the "ifc_base_name" and "name" are the same for # the first ifc created by namespace def _ns_add_ifc(self, name, ns_ifc, ifc_base_name=None, in_ifc=None, out_ifc=None, ipaddr=None, macaddr=None, fn=None, cmd=None, action="ok", disable_ipv6=False): if name in self.ipdbs: ns_ipdb = self.ipdbs[name] else: try: nl=NetNS(name) self.namespaces.append(nl) except KeyboardInterrupt: # remove the namespace if it has been created pyroute2.netns.remove(name) raise ns_ipdb = IPDB(nl) self.ipdbs[nl.netns] = ns_ipdb if disable_ipv6: cmd1 = ["sysctl", "-q", "-w", "net.ipv6.conf.default.disable_ipv6=1"] nsp = NSPopen(ns_ipdb.nl.netns, cmd1) nsp.wait(); nsp.release() try: ns_ipdb.interfaces.lo.up().commit() except pyroute2.ipdb.exceptions.CommitException: print("Warning, commit for lo failed, operstate may be unknown") if in_ifc: in_ifname = in_ifc.ifname with in_ifc as v: # move half of veth into namespace v.net_ns_fd = ns_ipdb.nl.netns else: # delete the potentially leaf-over veth interfaces ipr = IPRoute() for i in ipr.link_lookup(ifname='%sa' % ifc_base_name): ipr.link("del", index=i) ipr.close() try: out_ifc = self.ipdb.create(ifname="%sa" % ifc_base_name, kind="veth", peer="%sb" % ifc_base_name).commit() in_ifc = self.ipdb.interfaces[out_ifc.peer] in_ifname = in_ifc.ifname with in_ifc as v: v.net_ns_fd = ns_ipdb.nl.netns except KeyboardInterrupt: # explicitly remove the interface out_ifname = "%sa" % ifc_base_name if out_ifname in self.ipdb.interfaces: self.ipdb.interfaces[out_ifname].remove().commit() raise if out_ifc: out_ifc.up().commit() try: # this is a workaround for fc31 and possible other disto's. # when interface 'lo' is already up, do another 'up().commit()' # has issues in fc31. # the workaround may become permanent if we upgrade pyroute2 # in all machines. if 'state' in ns_ipdb.interfaces.lo.keys(): if ns_ipdb.interfaces.lo['state'] != 'up': ns_ipdb.interfaces.lo.up().commit() else: ns_ipdb.interfaces.lo.up().commit() except pyroute2.ipdb.exceptions.CommitException: print("Warning, commit for lo failed, operstate may be unknown") ns_ipdb.initdb() in_ifc = ns_ipdb.interfaces[in_ifname] with in_ifc as v: v.ifname = ns_ifc if ipaddr: v.add_ip("%s" % ipaddr) if macaddr: v.address = macaddr v.up() if disable_ipv6: cmd1 = ["sysctl", "-q", "-w", "net.ipv6.conf.%s.disable_ipv6=1" % out_ifc.ifname] subprocess.call(cmd1) if fn and out_ifc: self.ipdb.nl.tc("add", "ingress", out_ifc["index"], "ffff:") self.ipdb.nl.tc("add-filter", "bpf", out_ifc["index"], ":1", fd=fn.fd, name=fn.name, parent="ffff:", action=action, classid=1) if cmd: self.processes.append(NSPopen(ns_ipdb.nl.netns, cmd)) return (ns_ipdb, out_ifc, in_ifc) # helper function to create a namespace and a veth connecting it def _create_ns(self, name, in_ifc=None, out_ifc=None, ipaddr=None, macaddr=None, fn=None, cmd=None, action="ok", disable_ipv6=False): (ns_ipdb, out_ifc, in_ifc) = self._ns_add_ifc(name, "eth0", name, in_ifc, out_ifc, ipaddr, macaddr, fn, cmd, action, disable_ipv6) return (ns_ipdb, out_ifc, in_ifc) def release(self): if self.released: return self.released = True for p in self.processes: if p.released: continue try: p.kill() p.wait() except: pass finally: p.release() for name, db in self.ipdbs.items(): db.release() for ns in self.namespaces: ns.remove()