[Kimchi-devel] [PATCH] VLAN: Do not allow bridge to be the trunk device

[zhshzhou at linux.vnet.ibm.com]

From: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>

In Linux networking, a usual VLAN + bridge network setup is as the
following.

eth0 |-> eth0.10 -> br10 -> vnet101, vnet102, ...
     |-> eth0.20 -> br20 -> vnet201, vnet202, ...

While the eth0 trunk and VLAN interfaces provide the isolation service,
the bridges provide the switching inside the respective VLAN.

It's not very useful to have a bridge device as the trunk because the
VLAN interfaces on a trunk should be isolated.

This patch checks if the front-end submits an invalid setup to use a
bridge as the VLAN trunk device and raises exception.

Before this patch, if the user creates a bridged network over an
existing bridge with VLAN tag set. The back-end just ignores the VLAN
and creates an ordinary bridged network. After this patch, the back-end
raises an exception with an explanation in this case, so the user knows
what's going on and can re-try with correct parameters.

Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
---
 src/kimchi/i18n.py           | 1 +
 src/kimchi/model/networks.py | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
index 589c8cb..b463bd1 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -182,6 +182,7 @@ messages = {
     "KCHNET0016E": _("Specify name and type to create a Network"),
     "KCHNET0017E": _("Unable to delete network %(name)s. There are some virtual machines and/or templates linked to this network."),
     "KCHNET0018E": _("Unable to deactivate network %(name)s. There are some virtual machines and/or templates linked to this network."),
+    "KCHNET0019E": _("Bridge device %(name)s can not be the trunk device of a VLAN."),
 
     "KCHDR0001E": _("Debug report %(name)s does not exist"),
     "KCHDR0002E": _("Debug report tool not found in system"),
diff --git a/src/kimchi/model/networks.py b/src/kimchi/model/networks.py
index 0242156..531f614 100644
--- a/src/kimchi/model/networks.py
+++ b/src/kimchi/model/networks.py
@@ -151,6 +151,8 @@ class NetworksModel(object):
             raise MissingParameter("KCHNET0004E", {'name': params['name']})
 
         if netinfo.is_bridge(iface):
+            if 'vlan_id' in params:
+                raise InvalidParameter('KCHNET0019E', {'name': iface})
             params['bridge'] = iface
         elif netinfo.is_bare_nic(iface) or netinfo.is_bonding(iface):
             if params.get('vlan_id') is None:
-- 
1.8.5.3