[libvirt] [PATCHv3] Disable nwfilter driver when running unprivileged

[Ján Tomko]

When opening a new connection to the driver, nwfilterOpen
only succeeds if the driverState has been allocated.

Move the privilege check in driver initialization before
the state allocation to disable the driver.

This changes the nwfilter-define error from:
error: cannot create config directory (null): Bad address
To:
this function is not supported by the connection driver:
virNWFilterDefineXML

https://bugzilla.redhat.com/show_bug.cgi?id=1029266
---
v1: https://www.redhat.com/archives/libvir-list/2013-November/msg00368.html
v2: https://www.redhat.com/archives/libvir-list/2013-November/msg00374.html
forbid everything instead of just virNWFilterDefineXML
v3: cut a pair of holes into my brown paper bag

 src/nwfilter/nwfilter_driver.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/nwfilter/nwfilter_driver.c b/src/nwfilter/nwfilter_driver.c
index 6602d73..d521adf 100644
--- a/src/nwfilter/nwfilter_driver.c
+++ b/src/nwfilter/nwfilter_driver.c
@@ -174,6 +174,9 @@ nwfilterStateInitialize(bool privileged,
     char *base = NULL;
     DBusConnection *sysbus = NULL;
 
+    if (!privileged)
+        return 0;
+
 #if WITH_DBUS
     if (virDBusHasSystemBus() &&
         !(sysbus = virDBusGetSystemBus()))
@@ -190,9 +193,6 @@ nwfilterStateInitialize(bool privileged,
     driverState->watchingFirewallD = (sysbus != NULL);
     driverState->privileged = privileged;
 
-    if (!privileged)
-        return 0;
-
     nwfilterDriverLock(driverState);
 
     if (virNWFilterIPAddrMapInit() < 0)
-- 
1.8.3.2