topology: fix rate-limiting using class-based Qdiscs and HTB

1 files changed, 25 insertions, 18 deletions

diff --git a/rumba/elements/topology.py b/rumba/elements/topology.py
index f717a5a..87aeb4c 100644
--- a/rumba/elements/topology.py
+++ b/rumba/elements/topology.py
@@ -485,24 +485,31 @@ class LinkQuality(object):
     def rate(self):
         return self._rate
 
-    def build_command(self, ipcp):
-        cmd = []
+    def build_commands(self, ipcp):
+        netem_cmd = []
+        cmds = []
+        qref = "root"
 
         if ipcp in LinkQuality._active:
-            cmd.append("tc qdisc change dev %s root netem" % ipcp.ifname)
-        else:
-            cmd.append("tc qdisc add dev %s root netem" % ipcp.ifname)
-
-        if self.delay:
-            cmd.append(self.delay.build_command())
-
-        if self.loss:
-            cmd.append(self.loss.build_command())
+            cmds.append("tc qdisc del dev %s root" % ipcp.ifname)
 
         if self.rate:
-            cmd.append("rate %imbit" % self.rate)
-
-        return " ".join(cmd)
+            cmds.append("tc qdisc add dev %s root handle 1: htb default 1" \
+                        % ipcp.ifname)
+            cmds.append("tc class add dev %s parent 1: classid 1:1 htb rate %imbit" \
+                        % (ipcp.ifname, self.rate))
+            qref = "parent 1:1"
+
+        if self.delay or self.loss:
+            netem_cmd.append("tc qdisc add dev %s %s netem" \
+                             % (ipcp.ifname, qref))
+            if self.delay:
+                netem_cmd.append(self.delay.build_command())
+            if self.loss:
+                netem_cmd.append(self.loss.build_command())
+            cmds.append(" ".join(netem_cmd))
+
+        return cmds
 
     def apply(self, shim):
         if not (self.delay or self.loss or self.rate):
@@ -514,8 +521,8 @@ class LinkQuality(object):
                                  "the interface name is None")
                     continue
 
-                ipcp.node.execute_command(self.build_command(ipcp),
-                                          as_root=True)
+                ipcp.node.execute_commands(self.build_commands(ipcp),
+                                           as_root=True)
                 LinkQuality._active.add(ipcp)
 
     def deactivate(self, shim):
@@ -527,8 +534,8 @@ class LinkQuality(object):
                              "the interface name is None")
                 continue
 
-            ipcp.node.execute_command("tc qdisc del dev %s root "
-                                      "netem" % ipcp.ifname, as_root=True)
+            ipcp.node.execute_command("tc qdisc del dev %s root"
+                                      % ipcp.ifname, as_root=True)
             LinkQuality._active.remove(ipcp)