| 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() |
| ns_ipdb.interfaces.lo.up().commit() |
| 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_remove(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() |
| ns_ipdb.interfaces.lo.up().commit() |
| 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() |
| |
