be able to get/set bridge parameters too

src/netns/interface.py

@@ -23,6 +23,7 @@ class Interface(object):
         return "NETNSif-%.4x%.3x" % (os.getpid(), n)
 
     def __init__(self, index):
+        self._changeable_attributes = interface.changeable_attributes
         self._idx = index
 
     def __del__(self):
@@ -51,7 +52,11 @@ class NSInterface(Interface):
 
     # some black magic to automatically get/set interface attributes
     def __getattr__(self, name):
-        if (name not in interface.changeable_attributes):
+        try:
+            ca = object.__getattr__(self, '_changeable_attributes')
+        except:
+            ca = []
+        if (name not in ca):
             raise AttributeError("'%s' object has no attribute '%s'" %
                     (self.__class__.__name__, name))
         # I can use attributes now, as long as they are not in
@@ -60,7 +65,11 @@ class NSInterface(Interface):
         return getattr(iface, name)
 
     def __setattr__(self, name, value):
-        if (name not in interface.changeable_attributes):
+        try:
+            ca = object.__getattr__(self, '_changeable_attributes')
+        except:
+            ca = []
+        if (name not in ca):
             if name[0] != '_': # forbid anything that doesn't start with a _
                 raise AttributeError("'%s' object has no attribute '%s'" %
                         (self.__class__.__name__, name))
@@ -199,7 +208,11 @@ class ExternalInterface(Interface):
 
     # some black magic to automatically get/set interface attributes
     def __getattr__(self, name):
-        if (name not in interface.changeable_attributes):
+        try:
+            ca = object.__getattr__(self, '_changeable_attributes')
+        except:
+            ca = []
+        if (name not in ca):
             raise AttributeError("'%s' object has no attribute '%s'" %
                     (self.__class__.__name__, name))
         # I can use attributes now, as long as they are not in
@@ -208,7 +221,11 @@ class ExternalInterface(Interface):
         return getattr(iface, name)
 
     def __setattr__(self, name, value):
-        if (name not in interface.changeable_attributes):
+        try:
+            ca = object.__getattr__(self, '_changeable_attributes')
+        except:
+            ca = []
+        if (name not in ca):
             if name[0] != '_': # forbid anything that doesn't start with a _
                 raise AttributeError("'%s' object has no attribute '%s'" %
                         (self.__class__.__name__, name))
@@ -302,6 +319,7 @@ class Link(ExternalInterface):
 
         iface = netns.iproute.create_bridge(self._gen_br_name())
         super(Link, self).__init__(iface.index)
+        self._changeable_attributes = bridge.changeable_attributes
 
         self._ports = set()
         # register somewhere
@@ -391,22 +409,6 @@ def _make_setter(attr, conv = lambda x: x):
 class interface(object):
     """Class for internal use. It is mostly a data container used to easily
     pass information around; with some convenience methods."""
-    @classmethod
-    def parse_ip(cls, line):
-        """Parse a line of ouput from `ip -o link list' and construct and
-        return a new object with the data."""
-        match = re.search(r'^(\d+): (\S+): <(\S+)> mtu (\d+) qdisc \S+' +
-                r'.*link/\S+ ([0-9a-f:]+) brd ([0-9a-f:]+)', line)
-        flags = match.group(3).split(",")
-        return cls(
-                index   = match.group(1),
-                name    = match.group(2),
-                up      = "UP" in flags,
-                mtu     = match.group(4),
-                lladdr  = match.group(5),
-                arp     = not ("NOARP" in flags),
-                broadcast = match.group(6),
-                multicast = "MULTICAST" in flags)
 
     # information for other parts of the code
     changeable_attributes = ["name", "mtu", "lladdr", "broadcast", "up",
@@ -455,30 +457,71 @@ class interface(object):
         return self.__class__(self.index, name, up, mtu, lladdr, broadcast,
                 multicast, arp)
 
+class bridge(interface):
+    changeable_attributes = interface.changeable_attributes + ["stp",
+            "forward_delay", "hello_time", "ageing_time", "max_age"]
+
+    # Index should be read-only
+    stp = property(_make_getter("_stp"), _make_setter("_stp", _any_to_bool))
+    forward_delay = property(_make_getter("_forward_delay"),
+            _make_setter("_forward_delay", float))
+    hello_time = property(_make_getter("_hello_time"),
+            _make_setter("_hello_time", float))
+    ageing_time = property(_make_getter("_ageing_time"),
+            _make_setter("_ageing_time", float))
+    max_age = property(_make_getter("_max_age"),
+            _make_setter("_max_age", float))
+
+    @classmethod
+    def upgrade(cls, iface, *kargs, **kwargs):
+        """Upgrade a interface to a bridge."""
+        return cls(iface.index, iface.name, iface.up, iface.mtu, iface.lladdr,
+                iface.broadcast, iface.multicast, iface.arp, *kargs, **kwargs)
+
+    def __init__(self, index = None, name = None, up = None, mtu = None,
+            lladdr = None, broadcast = None, multicast = None, arp = None,
+            stp = None, forward_delay = None, hello_time = None,
+            ageing_time = None, max_age = None):
+        super(bridge, self).__init__(index, name, up, mtu, lladdr, broadcast,
+                multicast, arp)
+        self.stp            = stp
+        self.forward_delay  = forward_delay
+        self.hello_time     = hello_time
+        self.ageing_time    = ageing_time
+        self.max_age        = max_age
+
+    def __repr__(self):
+        s = "%s.%s(index = %s, name = %s, up = %s, mtu = %s, lladdr = %s, "
+        s += "broadcast = %s, multicast = %s, arp = %s, stp = %s, "
+        s += "forward_delay = %s, hello_time = %s, ageing_time = %s, "
+        s += "max_age = %s)"
+        return s % (self.__module__, self.__class__.__name__,
+                self.index.__repr__(), self.name.__repr__(),
+                self.up.__repr__(), self.mtu.__repr__(),
+                self.lladdr.__repr__(), self.broadcast.__repr__(),
+                self.multicast.__repr__(), self.arp.__repr__(),
+                self.stp.__repr__(), self.forward_delay.__repr__(),
+                self.hello_time.__repr__(), self.ageing_time.__repr__(),
+                self.max_age.__repr__())
+
+    def __sub__(self, o):
+        r = super(bridge, self).__sub__(o)
+        if type(o) == interface:
+            return r
+        r.stp           = None if self.stp == o.stp else self.stp
+        r.hello_time    = None if self.hello_time == o.hello_time else \
+                self.hello_time
+        r.forward_delay = None if self.forward_delay == o.forward_delay else \
+                self.forward_delay
+        r.ageing_time   = None if self.ageing_time == o.ageing_time else \
+                self.ageing_time
+        r.max_age       = None if self.max_age == o.max_age else self.max_age
+        return r
+
 class address(object):
     """Class for internal use. It is mostly a data container used to easily
     pass information around; with some convenience methods. __eq__ and __hash__
     are defined just to be able to easily find duplicated addresses."""
-    @classmethod
-    def parse_ip(cls, line):
-        """Parse a line of ouput from `ip -o addr list' (after trimming the
-        index and interface name) and construct and return a new object with
-        the data."""
-        match = re.search(r'^inet ([0-9.]+)/(\d+)(?: brd ([0-9.]+))?', line)
-        if match != None:
-            return ipv4address(
-                address     = match.group(1),
-                prefix_len  = match.group(2),
-                broadcast   = match.group(3))
-
-        match = re.search(r'^inet6 ([0-9a-f:]+)/(\d+)', line)
-        if match != None:
-            return ipv6address(
-                address     = match.group(1),
-                prefix_len  = match.group(2))
-
-        raise RuntimeError("Problems parsing ip command output")
-
     # broadcast is not taken into account for differentiating addresses
     def __eq__(self, o):
         if not isinstance(o, address):

src/netns/iproute.py

 # vim:ts=4:sw=4:et:ai:sts=4
 
-import re, subprocess, sys
+import os, re, subprocess, sys
 import netns.interface
 
 # XXX: ideally this should be replaced by netlink communication
@@ -25,7 +25,18 @@ def get_if_data():
             continue
         match = re.search(r'^(\d+):\s+(.*)', line)
         idx = int(match.group(1))
-        i = netns.interface.interface.parse_ip(line)
+        match = re.search(r'^(\d+): (\S+): <(\S+)> mtu (\d+) qdisc \S+' +
+                r'.*link/\S+ ([0-9a-f:]+) brd ([0-9a-f:]+)', line)
+        flags = match.group(3).split(",")
+        i = netns.interface.interface(
+                index   = match.group(1),
+                name    = match.group(2),
+                up      = "UP" in flags,
+                mtu     = match.group(4),
+                lladdr  = match.group(5),
+                arp     = not ("NOARP" in flags),
+                broadcast = match.group(6),
+                multicast = "MULTICAST" in flags)
         byidx[idx] = bynam[i.name] = i
     return byidx, bynam
 
@@ -146,9 +157,25 @@ def get_addr_data():
         if match.group(3):
             bynam[name] = byidx[idx] = []
             continue # link info
-        bynam[name].append(netns.interface.address.parse_ip(match.group(4)))
+        bynam[name].append(_parse_ip_addr(match.group(4)))
     return byidx, bynam
 
+def _parse_ip_addr(line):
+    match = re.search(r'^inet ([0-9.]+)/(\d+)(?: brd ([0-9.]+))?', line)
+    if match != None:
+        return ipv4address(
+                address     = match.group(1),
+                prefix_len  = match.group(2),
+                broadcast   = match.group(3))
+
+        match = re.search(r'^inet6 ([0-9a-f:]+)/(\d+)', line)
+    if match != None:
+        return ipv6address(
+                address     = match.group(1),
+                prefix_len  = match.group(2))
+
+        raise RuntimeError("Problems parsing ip command output")
+
 def add_addr(iface, address):
     ifname = _get_if_name(iface)
     addresses = get_addr_data()[1][ifname]
@@ -194,32 +221,34 @@ def set_addr(iface, addresses, recover = True):
 # Bridge handling
 
 def get_br_data():
-    ifdata = get_if_data()
-    ipcmd = subprocess.Popen(["brctl", "show"], stdout = subprocess.PIPE)
-    ipdata = ipcmd.communicate()[0]
-    assert ipcmd.wait() == 0
+    # brctl stinks too much; it is better to directly use sysfs, it is probably
+    # stable by now
+    def readval(fname):
+        f = file(fname)
+        return f.readline().strip()
 
     byidx = {}
     bynam = {}
     ports = {}
-    last = None
-    for line in ipdata.split("\n")[1:]: # skip header
-        if line == "":
-            continue
-        if last:
-            match = re.search(r'^\s+(\S+)$', line)
-            if match:
-                ports[last].append(ifdata[1][match.group(1)])
+    ifdata = get_if_data()
+    for i in ifdata[1]: # by name
+        p = '/sys/class/net/%s/bridge/' % i
+        p2 = '/sys/class/net/%s/brif/' % i
+        try:
+            os.stat(p)
+        except:
             continue
+        params = dict(
+                stp             = readval(p + 'stp_state'),
+                forward_delay   = float(readval(p + 'forward_delay')) / 100,
+                hello_time      = float(readval(p + 'hello_time')) / 100,
+                ageing_time     = float(readval(p + 'ageing_time')) / 100,
+                max_age         = float(readval(p + 'max_age')) / 100)
+        iface = ifdata[1][i]
+        bynam[i] = byidx[iface.index] = netns.interface.bridge.upgrade(
+                iface, **params)
+        ports[iface.index] = [ifdata[1][x].index for x in os.listdir(p2)]
 
-        match = re.search(r'^(\S+)\s+\S+\s+\S+\s*(\S+)?', line)
-        if not match:
-            raise RuntimeError("Invalid `brctl' command output")
-        name = match.group(1)
-        last = idx = ifdata[1][name].index
-
-        bynam[name] = byidx[idx] = ifdata[1][name]
-        ports[idx] = []
     return byidx, bynam, ports
 
 def create_bridge(br):
@@ -242,6 +271,39 @@ def del_bridge(br):
     brname = _get_if_name(br)
     _execute(["brctl", "delbr", brname])
 
+def set_bridge(br, recover = True):
+    def saveval(fname, val):
+        f = file(fname, 'w')
+        f.write(str(val))
+        f.close()
+    def do_cmds(basename, cmds, orig_br):
+        for n, v in cmds:
+            try:
+                saveval(basename + n, v)
+            except:
+                if recover:
+                    set_bridge(orig_br, recover = False) # rollback
+                    set_if(orig_br, recover = False) # rollback
+                    raise
+
+    orig_br = get_br_data()[1][_get_if_name(br)]
+    diff = br - orig_br # Only set what's needed
+
+    cmds = []
+    if diff.stp != None:
+        cmds.append(('stp_state', int(diff.stp)))
+    if diff.forward_delay != None:
+        cmds.append(('forward_delay', int(diff.forward_delay)))
+    if diff.hello_time != None:
+        cmds.append(('hello_time', int(diff.hello_time)))
+    if diff.ageing_time != None:
+        cmds.append(('ageing_time', int(diff.ageing_time)))
+    if diff.max_age != None:
+        cmds.append(('max_age', int(diff.max_age)))
+
+    set_if(diff)
+    do_cmds('/sys/class/net/%s/bridge/' % br.name, cmds, orig_br)
+
 def add_bridge_port(br, iface):
     ifname = _get_if_name(iface)
     brname = _get_if_name(br)