Organize things a little

src/netns/environ.py

+# vim:ts=4:sw=4:et:ai:sts=4
+
+import os
+
+__all__ = ["ip_path", "tc_path", "brctl_path", "hz"]
+
+def _find_bin(name):
+    for pref in ("/", "/usr/", "/usr/local/"):
+        for d in ("bin/", "sbin/"):
+            try:
+                os.stat(pref + d + name)
+                return pref + d + name
+            except OSError, e:
+                if e.errno != os.errno.ENOENT:
+                    raise
+    raise RuntimeError("Cannot find `%s' command, impossible to continue." %
+            name)
+
+ip_path = _find_bin("ip")
+tc_path = _find_bin("tc")
+brctl_path = _find_bin("brctl")
+sysctl_path = _find_bin("sysctl")
+
+# Seems this is completely bogus. At least, we can assume that the internal HZ
+# is bigger than this.
+hz = os.sysconf("SC_CLK_TCK")
+
+try:
+    os.stat("/sys/class/net")
+except:
+    raise RuntimeError("Sysfs does not seem to be mounted, impossible to " +
+            "continue.")
+

src/netns/interface.py

@@ -50,7 +50,8 @@ class NSInterface(Interface):
         # Disable auto-configuration
         # you wish: need to take into account the nonetns mode; plus not
         # touching some pre-existing ifaces
-        #node.system(['/sbin/sysctl', '-w', 'net.ipv6.conf.%s.autoconf=0' % self.name])
+        #node.system([sysctl_path, '-w', 'net.ipv6.conf.%s.autoconf=0' %
+        #self.name])
         node._add_interface(self)
 
     # some black magic to automatically get/set interface attributes

src/netns/iproute.py

 # vim:ts=4:sw=4:et:ai:sts=4
 
 import copy, os, re, socket, subprocess, sys
-
-def _find_bin(name):
-    for pref in ("/", "/usr/", "/usr/local/"):
-        for d in ("bin/", "sbin/"):
-            try:
-                os.stat(pref + d + name)
-                return pref + d + name
-            except OSError, e:
-                if e.errno != os.errno.ENOENT:
-                    raise
-    raise RuntimeError("Cannot find `%s' command, impossible to continue." %
-            name)
-
-_ip = _find_bin("ip")
-_tc = _find_bin("tc")
-_brctl = _find_bin("brctl")
-# Seems this is completely bogus. At least, we can assume that the internal HZ
-# is bigger than this.
-_hz = os.sysconf("SC_CLK_TCK")
-
-try:
-    os.stat("/sys/class/net")
-except:
-    raise RuntimeError("Sysfs does not seem to be mounted, impossible to " +
-            "continue.")
+from netns.environ import *
 
 # helpers
 def _any_to_bool(any):
@@ -311,7 +287,7 @@ def get_if_data():
 
     In each dictionary, values are interface objects.
     """
-    ipcmd = subprocess.Popen([_ip, "-o", "link", "list"],
+    ipcmd = subprocess.Popen([ip_path, "-o", "link", "list"],
         stdout = subprocess.PIPE)
     ipdata = ipcmd.communicate()[0]
     assert ipcmd.wait() == 0
@@ -363,7 +339,7 @@ def create_if_pair(if1, if2):
         if iface[i].mtu:
             cmd[i] += ["mtu", str(iface[i].mtu)]
 
-    cmd = [_ip, "link", "add"] + cmd[0] + ["type", "veth", "peer"] + cmd[1]
+    cmd = [ip_path, "link", "add"] + cmd[0] + ["type", "veth", "peer"] + cmd[1]
     _execute(cmd)
     try:
         set_if(if1)
@@ -381,7 +357,7 @@ def create_if_pair(if1, if2):
 
 def del_if(iface):
     ifname = _get_if_name(iface)
-    _execute([_ip, "link", "del", ifname])
+    _execute([ip_path, "link", "del", ifname])
 
 def set_if(iface, recover = True):
     def do_cmds(cmds, orig_iface):
@@ -398,7 +374,7 @@ def set_if(iface, recover = True):
 
     # Name goes first
     if diff.name:
-        _ils = [_ip, "link", "set", "dev"]
+        _ils = [ip_path, "link", "set", "dev"]
         cmds = [_ils + [orig_iface.name, "name", diff.name]]
         if orig_iface.up:
             # iface needs to be down
@@ -407,7 +383,7 @@ def set_if(iface, recover = True):
         do_cmds(cmds, orig_iface)
 
     # I need to use the new name after a name change, duh!
-    _ils = [_ip, "link", "set", "dev", diff.name or orig_iface.name]
+    _ils = [ip_path, "link", "set", "dev", diff.name or orig_iface.name]
     cmds = []
     if diff.lladdr:
         if orig_iface.up:
@@ -432,12 +408,12 @@ def set_if(iface, recover = True):
 
 def change_netns(iface, netns):
     ifname = _get_if_name(iface)
-    _execute([_ip, "link", "set", "dev", ifname, "netns", str(netns)])
+    _execute([ip_path, "link", "set", "dev", ifname, "netns", str(netns)])
 
 # Address handling
 
 def get_addr_data():
-    ipcmd = subprocess.Popen([_ip, "-o", "addr", "list"],
+    ipcmd = subprocess.Popen([ip_path, "-o", "addr", "list"],
         stdout = subprocess.PIPE)
     ipdata = ipcmd.communicate()[0]
     assert ipcmd.wait() == 0
@@ -479,7 +455,7 @@ def add_addr(iface, address):
     addresses = get_addr_data()[1][ifname]
     assert address not in addresses
 
-    cmd = [_ip, "addr", "add", "dev", ifname, "local",
+    cmd = [ip_path, "addr", "add", "dev", ifname, "local",
             "%s/%d" % (address.address, int(address.prefix_len))]
     if hasattr(address, "broadcast"):
         cmd += ["broadcast", address.broadcast if address.broadcast else "+"]
@@ -490,7 +466,7 @@ def del_addr(iface, address):
     addresses = get_addr_data()[1][ifname]
     assert address in addresses
 
-    cmd = [_ip, "addr", "del", "dev", ifname, "local",
+    cmd = [ip_path, "addr", "del", "dev", ifname, "local",
             "%s/%d" % (address.address, int(address.prefix_len))]
     _execute(cmd)
 
@@ -564,7 +540,7 @@ def create_bridge(br):
     if isinstance(br, str):
         br = interface(name = br)
     assert br.name
-    _execute([_brctl, "addbr", br.name])
+    _execute([brctl_path, "addbr", br.name])
     try:
         set_if(br)
     except:
@@ -578,7 +554,7 @@ def create_bridge(br):
 
 def del_bridge(br):
     brname = _get_if_name(br)
-    _execute([_brctl, "delbr", brname])
+    _execute([brctl_path, "delbr", brname])
 
 def set_bridge(br, recover = True):
     def saveval(fname, val):
@@ -617,20 +593,20 @@ def set_bridge(br, recover = True):
 def add_bridge_port(br, iface):
     ifname = _get_if_name(iface)
     brname = _get_if_name(br)
-    _execute([_brctl, "addif", brname, ifname])
+    _execute([brctl_path, "addif", brname, ifname])
 
 def del_bridge_port(br, iface):
     ifname = _get_if_name(iface)
     brname = _get_if_name(br)
-    _execute([_brctl, "delif", brname, ifname])
+    _execute([brctl_path, "delif", brname, ifname])
 
 def get_all_route_data():
-    #ipcmd = subprocess.Popen([_ip, "-o", "route", "list", "table", "all"],
-    ipcmd = subprocess.Popen([_ip, "-o", "route", "list"],
+    #ipcmd = subprocess.Popen([ip_path, "-o", "route", "list", "table", "all"],
+    ipcmd = subprocess.Popen([ip_path, "-o", "route", "list"],
         stdout = subprocess.PIPE)
     ipdata = ipcmd.communicate()[0]
     assert ipcmd.wait() == 0
-    ipcmd = subprocess.Popen([_ip, "-o", "-f", "inet6", "route", "list"],
+    ipcmd = subprocess.Popen([ip_path, "-o", "-f", "inet6", "route", "list"],
         stdout = subprocess.PIPE)
     ipdata += ipcmd.communicate()[0]
     assert ipcmd.wait() == 0
@@ -678,7 +654,7 @@ def del_route(route):
     _add_del_route("del", route)
 
 def _add_del_route(action, route):
-    cmd = [_ip, "route", action]
+    cmd = [ip_path, "route", action]
     if route.tipe != "unicast":
         cmd += [route.tipe]
     if route.prefix:
@@ -694,7 +670,8 @@ def _add_del_route(action, route):
 # TC stuff
 
 def get_tc_tree():
-    tccmd = subprocess.Popen([_tc, "qdisc", "show"], stdout = subprocess.PIPE)
+    tccmd = subprocess.Popen([tc_path, "qdisc", "show"],
+            stdout = subprocess.PIPE)
     tcdata = tccmd.communicate()[0]
     assert tccmd.wait() == 0
 
@@ -852,7 +829,7 @@ def clear_tc(iface):
     if tcdata[iface.index] == None:
         return
     # Any other case, we clean
-    _execute([_tc, "qdisc", "del", "dev", iface.name, "root"])
+    _execute([tc_path, "qdisc", "del", "dev", iface.name, "root"])
 
 def set_tc(iface, bandwidth = None, delay = None, delay_jitter = None,
         delay_correlation = None, delay_distribution = None,
@@ -868,7 +845,7 @@ def set_tc(iface, bandwidth = None, delay = None, delay_jitter = None,
     commands = []
     if tcdata[iface.index] == 'foreign':
         # Avoid the overhead of calling tc+ip again
-        commands.append([_tc, "qdisc", "del", "dev", iface.name, "root"])
+        commands.append([tc_path, "qdisc", "del", "dev", iface.name, "root"])
         tcdata[iface.index] = {'qdiscs':  []}
 
     has_netem = 'netem' in tcdata[iface.index]['qdiscs']
@@ -884,18 +861,19 @@ def set_tc(iface, bandwidth = None, delay = None, delay_jitter = None,
     else:
         # Too much work to do better :)
         if has_netem or has_tbf:
-            commands.append([_tc, "qdisc", "del", "dev", iface.name, "root"])
+            commands.append([tc_path, "qdisc", "del", "dev", iface.name,
+                "root"])
         cmd = "add"
 
     if bandwidth:
         rate = "%dbit" % int(bandwidth)
         mtu = ifdata[iface.index].mtu
-        burst = max(mtu, int(bandwidth) / _hz)
+        burst = max(mtu, int(bandwidth) / hz)
         limit = burst * 2 # FIXME?
         handle = "1:"
         if cmd == "change":
             handle = "%d:" % int(tcdata[iface.index]["qdiscs"]["tbf"])
-        command = [_tc, "qdisc", cmd, "dev", iface.name, "root", "handle",
+        command = [tc_path, "qdisc", cmd, "dev", iface.name, "root", "handle",
                 handle, "tbf", "rate", rate, "limit", str(limit), "burst",
                 str(burst)]
         commands.append(command)
@@ -904,7 +882,7 @@ def set_tc(iface, bandwidth = None, delay = None, delay_jitter = None,
         handle = "2:"
         if cmd == "change":
             handle = "%d:" % int(tcdata[iface.index]["qdiscs"]["netem"])
-        command = [_tc, "qdisc", cmd, "dev", iface.name, "handle", handle]
+        command = [tc_path, "qdisc", cmd, "dev", iface.name, "handle", handle]
         if bandwidth:
             parent = "1:"
             if cmd == "change":

src/netns/node.py

@@ -2,7 +2,7 @@
 # vim:ts=4:sw=4:et:ai:sts=4
 
 import os, socket, sys, traceback, unshare, weakref
-import netns.protocol, netns.subprocess_
+import netns.environ, netns.protocol, netns.subprocess_
 
 __all__ = ['Node', 'get_nodes']
 
@@ -161,8 +161,9 @@ def _start_child(debug, nonetns):
             # create new name space
             unshare.unshare(unshare.CLONE_NEWNET)
             # Enable packet forwarding
-            netns.iproute._execute(['sysctl', '-w', 'net.ipv4.ip_forward=1'])
-            netns.iproute._execute(['sysctl', '-w',
+            netns.iproute._execute([netns.environ.sysctl_path, '-w',
+                'net.ipv4.ip_forward=1'])
+            netns.iproute._execute([netns.environ.sysctl_path, '-w',
                 'net.ipv6.conf.default.forwarding=1'])
         srv.run()
     except BaseException, e:

t/test_interfaces.py

@@ -2,9 +2,9 @@
 # vim:ts=4:sw=4:et:ai:sts=4
 
 from test_util import get_devs, get_devs_netns
+from netns.environ import *
 import netns, test_util
-import os
-import unittest
+import os, unittest
 
 class TestUtils(unittest.TestCase):
     def test_utils(self):
@@ -80,7 +80,7 @@ class TestInterfaces(unittest.TestCase):
         self.assertTrue(devs[if0.name]['up'])
 
         # Verify that data is actually read from the kernel
-        r = node0.system(["ip", "link", "set", if0.name, "mtu", "1500"])
+        r = node0.system([ip_path, "link", "set", if0.name, "mtu", "1500"])
         self.assertEquals(r, 0)
         devs = get_devs_netns(node0)
         self.assertEquals(devs[if0.name]['mtu'], 1500)
@@ -126,8 +126,8 @@ class TestWithDummy(unittest.TestCase):
     def test_interface_migration(self):
         node = netns.Node()
         self.dummyname = "dummy%d" % os.getpid()
-        self.assertEquals(
-                os.system("ip link add name %s type dummy" % self.dummyname), 0)
+        self.assertEquals(os.system("%s link add name %s type dummy" %
+                    (ip_path, self.dummyname)), 0)
         devs = get_devs()
         self.assertTrue(self.dummyname in devs)
         dummyidx = devs[self.dummyname]['idx']
@@ -152,7 +152,7 @@ class TestWithDummy(unittest.TestCase):
     def tearDown(self):
         # oops here
         if hasattr(self, 'dummyname'):
-            os.system("ip link del %s" % self.dummyname)
+            os.system("%s link del %s" % (ip_path, self.dummyname))
 
 # FIXME: Links
 

t/test_link.py

@@ -2,7 +2,7 @@
 # vim:ts=4:sw=4:et:ai:sts=4
 
 import os, unittest
-import netns, test_util
+import netns, test_util, netns.environ
 
 class TestLink(unittest.TestCase):
     @test_util.skipUnless(os.getuid() == 0, "Test requires root privileges")
@@ -46,7 +46,7 @@ class TestLink(unittest.TestCase):
         # Test strange rules handling
         os.system(("%s qd add dev %s root prio bands 3 " +
             "priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1") %
-            (netns.iproute._tc, i1.control.name))
+            (netns.environ.tc_path, i1.control.name))
         tcdata = netns.iproute.get_tc_data()[0]
         self.assertEquals(tcdata[i1.control.index], "foreign")
         l.set_parameters(bandwidth = 13107200) # 100 mbits

t/test_node.py

 #!/usr/bin/env python
 # vim:ts=4:sw=4:et:ai:sts=4
 
-import netns, test_util
+import netns, netns.environ, test_util
 import os, signal, subprocess, sys, time
 import unittest
 
 class TestNode(unittest.TestCase):
-#    def setUp(self):
-#        pass
     @test_util.skipUnless(os.getuid() == 0, "Test requires root privileges")
     def test_node(self):
         node = netns.Node()
@@ -41,8 +39,8 @@ class TestNode(unittest.TestCase):
             link.connect(ifa)
             link.connect(ifb)
         def get_devs():
-            ipcmd = subprocess.Popen(["ip", "-o", "link", "list"],
-                    stdout = subprocess.PIPE)
+            ipcmd = subprocess.Popen([netns.environ.ip_path, "-o", "link",
+                "list"], stdout = subprocess.PIPE)
             (outdata, errdata) = ipcmd.communicate()
             ipcmd.wait()
             return outdata.split("\n")

t/test_util.py

@@ -3,6 +3,7 @@
 
 import os, re, subprocess, sys
 import netns.subprocess_
+from netns.environ import *
 
 def process_ipcmd(str):
     cur = None
@@ -53,13 +54,13 @@ def process_ipcmd(str):
     return out
 
 def get_devs():
-    ipcmd = subprocess.Popen(["ip", "addr", "list"],
+    ipcmd = subprocess.Popen([ip_path, "addr", "list"],
             stdout = subprocess.PIPE)
     (outdata, errdata) = ipcmd.communicate()
     return process_ipcmd(outdata)
 
 def get_devs_netns(node):
-    out = netns.subprocess_.backticks_raise(node, ["ip", "addr", "list"])
+    out = netns.subprocess_.backticks_raise(node, [ip_path, "addr", "list"])
     return process_ipcmd(out)
 
 def make_linux_ver(string):