nwfilter: remove virt driver callback layer for rebuilding filters

Now that the nwfilter driver keeps a list of bindings that it has
created, there is no need for the complex virt driver callbacks. It is
possible to simply iterate of the list of recorded filter bindings.

This means that rebuilding filters no longer has to acquire any locks on
the virDomainObj objects, as they're never touched.

Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

src/conf/nwfilter_conf.c

@@ -2819,121 +2819,6 @@ virNWFilterSaveConfig(const char *configDir,
 }
 
 
-int nCallbackDriver;
-#define MAX_CALLBACK_DRIVER 10
-static virNWFilterCallbackDriverPtr callbackDrvArray[MAX_CALLBACK_DRIVER];
-
-void
-virNWFilterRegisterCallbackDriver(virNWFilterCallbackDriverPtr cbd)
-{
-    if (nCallbackDriver < MAX_CALLBACK_DRIVER)
-        callbackDrvArray[nCallbackDriver++] = cbd;
-}
-
-
-void
-virNWFilterUnRegisterCallbackDriver(virNWFilterCallbackDriverPtr cbd)
-{
-    size_t i = 0;
-
-    while (i < nCallbackDriver && callbackDrvArray[i] != cbd)
-        i++;
-
-    if (i < nCallbackDriver) {
-        memmove(&callbackDrvArray[i], &callbackDrvArray[i+1],
-                (nCallbackDriver - i - 1) * sizeof(callbackDrvArray[i]));
-        callbackDrvArray[i] = 0;
-        nCallbackDriver--;
-    }
-}
-
-
-void
-virNWFilterCallbackDriversLock(void)
-{
-    size_t i;
-
-    for (i = 0; i < nCallbackDriver; i++)
-        callbackDrvArray[i]->vmDriverLock();
-}
-
-
-void
-virNWFilterCallbackDriversUnlock(void)
-{
-    size_t i;
-
-    for (i = 0; i < nCallbackDriver; i++)
-        callbackDrvArray[i]->vmDriverUnlock();
-}
-
-
-static virDomainObjListIterator virNWFilterDomainFWUpdateCB;
-static void *virNWFilterDomainFWUpdateOpaque;
-
-/**
- * virNWFilterInstFiltersOnAllVMs:
- * Apply all filters on all running VMs. Don't terminate in case of an
- * error. This should be called upon reloading of the driver.
- */
-int
-virNWFilterInstFiltersOnAllVMs(void)
-{
-    size_t i;
-    struct domUpdateCBStruct cb = {
-        .opaque = virNWFilterDomainFWUpdateOpaque,
-        .step = STEP_APPLY_CURRENT,
-        .skipInterfaces = NULL, /* not needed */
-    };
-
-    for (i = 0; i < nCallbackDriver; i++)
-        callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
-                                             &cb);
-
-    return 0;
-}
-
-
-int
-virNWFilterTriggerVMFilterRebuild(void)
-{
-    size_t i;
-    int ret = 0;
-    struct domUpdateCBStruct cb = {
-        .opaque = virNWFilterDomainFWUpdateOpaque,
-        .step = STEP_APPLY_NEW,
-        .skipInterfaces = virHashCreate(0, NULL),
-    };
-
-    if (!cb.skipInterfaces)
-        return -1;
-
-    for (i = 0; i < nCallbackDriver; i++) {
-        if (callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
-                                                 &cb) < 0)
-            ret = -1;
-    }
-
-    if (ret < 0) {
-        cb.step = STEP_TEAR_NEW; /* rollback */
-
-        for (i = 0; i < nCallbackDriver; i++)
-            callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
-                                                 &cb);
-    } else {
-        cb.step = STEP_TEAR_OLD; /* switch over */
-
-        for (i = 0; i < nCallbackDriver; i++)
-            callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
-                                                 &cb);
-    }
-
-    virHashFree(cb.skipInterfaces);
-
-    return ret;
-}
-
-
 int
 virNWFilterDeleteDef(const char *configDir,
                      virNWFilterDefPtr def)
@@ -3204,16 +3089,18 @@ virNWFilterDefFormat(const virNWFilterDef *def)
     return NULL;
 }
 
+static virNWFilterTriggerRebuildCallback rebuildCallback;
+static void *rebuildOpaque;
 
 int
-virNWFilterConfLayerInit(virDomainObjListIterator domUpdateCB,
+virNWFilterConfLayerInit(virNWFilterTriggerRebuildCallback cb,
                          void *opaque)
 {
     if (initialized)
         return -1;
 
-    virNWFilterDomainFWUpdateCB = domUpdateCB;
+    rebuildCallback = cb;
-    virNWFilterDomainFWUpdateOpaque = opaque;
+    rebuildOpaque = opaque;
 
     initialized = true;
 
@@ -3233,8 +3120,17 @@ virNWFilterConfLayerShutdown(void)
     virRWLockDestroy(&updateLock);
 
     initialized = false;
-    virNWFilterDomainFWUpdateOpaque = NULL;
+    rebuildCallback = NULL;
-    virNWFilterDomainFWUpdateCB = NULL;
+    rebuildOpaque = NULL;
+}
+
+
+int
+virNWFilterTriggerRebuild(void)
+{
+    if (rebuildCallback)
+        return rebuildCallback(rebuildOpaque);
+    return 0;
 }
 
 

src/conf/nwfilter_conf.h

@@ -546,20 +546,6 @@ struct _virNWFilterDef {
 };
 
 
-typedef enum {
-    STEP_APPLY_NEW,
-    STEP_TEAR_NEW,
-    STEP_TEAR_OLD,
-    STEP_APPLY_CURRENT,
-} UpdateStep;
-
-struct domUpdateCBStruct {
-    void *opaque;
-    UpdateStep step;
-    virHashTablePtr skipInterfaces;
-};
-
-
 void
 virNWFilterRuleDefFree(virNWFilterRuleDefPtr def);
 
@@ -567,7 +553,7 @@ void
 virNWFilterDefFree(virNWFilterDefPtr def);
 
 int
-virNWFilterTriggerVMFilterRebuild(void);
+virNWFilterTriggerRebuild(void);
 
 int
 virNWFilterDeleteDef(const char *configDir,
@@ -599,44 +585,15 @@ virNWFilterReadLockFilterUpdates(void);
 void
 virNWFilterUnlockFilterUpdates(void);
 
+typedef int (*virNWFilterTriggerRebuildCallback)(void *opaque);
+
 int
-virNWFilterConfLayerInit(virDomainObjListIterator domUpdateCB,
+virNWFilterConfLayerInit(virNWFilterTriggerRebuildCallback cb,
                          void *opaque);
 
 void
 virNWFilterConfLayerShutdown(void);
 
-int
-virNWFilterInstFiltersOnAllVMs(void);
-
-typedef int
-(*virNWFilterRebuild)(virDomainObjListIterator domUpdateCB,
-                      void *data);
-
-typedef void
-(*virNWFilterVoidCall)(void);
-
-typedef struct _virNWFilterCallbackDriver virNWFilterCallbackDriver;
-typedef virNWFilterCallbackDriver *virNWFilterCallbackDriverPtr;
-struct _virNWFilterCallbackDriver {
-    const char *name;
-
-    virNWFilterRebuild vmFilterRebuild;
-    virNWFilterVoidCall vmDriverLock;
-    virNWFilterVoidCall vmDriverUnlock;
-};
-
-void
-virNWFilterRegisterCallbackDriver(virNWFilterCallbackDriverPtr);
-
-void
-virNWFilterUnRegisterCallbackDriver(virNWFilterCallbackDriverPtr);
-
-void
-virNWFilterCallbackDriversLock(void);
-
-void
-virNWFilterCallbackDriversUnlock(void);
 
 char *
 virNWFilterPrintTCPFlags(uint8_t flags);

src/conf/virnwfilterobj.c

@@ -276,7 +276,7 @@ virNWFilterObjTestUnassignDef(virNWFilterObjPtr obj)
 
     obj->wantRemoved = true;
     /* trigger the update on VMs referencing the filter */
-    if (virNWFilterTriggerVMFilterRebuild() < 0)
+    if (virNWFilterTriggerRebuild() < 0)
         rc = -1;
 
     obj->wantRemoved = false;
@@ -358,7 +358,7 @@ virNWFilterObjListAssignDef(virNWFilterObjListPtr nwfilters,
 
         obj->newDef = def;
         /* trigger the update on VMs referencing the filter */
-        if (virNWFilterTriggerVMFilterRebuild() < 0) {
+        if (virNWFilterTriggerRebuild() < 0) {
             obj->newDef = NULL;
             virNWFilterObjUnlock(obj);
             return NULL;

src/libvirt_private.syms

@@ -787,8 +787,6 @@ virDomainNumatuneSpecifiedMaxNode;
 
 
 # conf/nwfilter_conf.h
-virNWFilterCallbackDriversLock;
-virNWFilterCallbackDriversUnlock;
 virNWFilterChainSuffixTypeToString;
 virNWFilterConfLayerInit;
 virNWFilterConfLayerShutdown;
@@ -797,12 +795,10 @@ virNWFilterDefFree;
 virNWFilterDefParseFile;
 virNWFilterDefParseString;
 virNWFilterDeleteDef;
-virNWFilterInstFiltersOnAllVMs;
 virNWFilterJumpTargetTypeToString;
 virNWFilterPrintStateMatchFlags;
 virNWFilterPrintTCPFlags;
 virNWFilterReadLockFilterUpdates;
-virNWFilterRegisterCallbackDriver;
 virNWFilterRuleActionTypeToString;
 virNWFilterRuleDirectionTypeToString;
 virNWFilterRuleIsProtocolEthernet;
@@ -810,9 +806,8 @@ virNWFilterRuleIsProtocolIPv4;
 virNWFilterRuleIsProtocolIPv6;
 virNWFilterRuleProtocolTypeToString;
 virNWFilterSaveConfig;
-virNWFilterTriggerVMFilterRebuild;
+virNWFilterTriggerRebuild;
 virNWFilterUnlockFilterUpdates;
-virNWFilterUnRegisterCallbackDriver;
 virNWFilterWriteLockFilterUpdates;
 
 

src/lxc/lxc_driver.c

@@ -66,7 +66,6 @@
 #include "virfdstream.h"
 #include "domain_audit.h"
 #include "domain_nwfilter.h"
-#include "nwfilter_conf.h"
 #include "virinitctl.h"
 #include "virnetdev.h"
 #include "virnetdevtap.h"
@@ -95,31 +94,6 @@ static int lxcStateInitialize(bool privileged,
 static int lxcStateCleanup(void);
 virLXCDriverPtr lxc_driver = NULL;
 
-/* callbacks for nwfilter */
-static int
-lxcVMFilterRebuild(virDomainObjListIterator iter, void *data)
-{
-    return virDomainObjListForEach(lxc_driver->domains, iter, data);
-}
-
-static void
-lxcVMDriverLock(void)
-{
-    lxcDriverLock(lxc_driver);
-}
-
-static void
-lxcVMDriverUnlock(void)
-{
-    lxcDriverUnlock(lxc_driver);
-}
-
-static virNWFilterCallbackDriver lxcCallbackDriver = {
-    .name = "LXC",
-    .vmFilterRebuild = lxcVMFilterRebuild,
-    .vmDriverLock = lxcVMDriverLock,
-    .vmDriverUnlock = lxcVMDriverUnlock,
-};
 
 /**
  * lxcDomObjFromDomain:
@@ -1672,7 +1646,6 @@ static int lxcStateInitialize(bool privileged,
                                        NULL, NULL) < 0)
         goto cleanup;
 
-    virNWFilterRegisterCallbackDriver(&lxcCallbackDriver);
     virObjectUnref(caps);
     return 0;
 
@@ -1744,7 +1717,6 @@ static int lxcStateCleanup(void)
     if (lxc_driver == NULL)
         return -1;
 
-    virNWFilterUnRegisterCallbackDriver(&lxcCallbackDriver);
     virObjectUnref(lxc_driver->domains);
     virObjectUnref(lxc_driver->domainEventState);
 

src/nwfilter/nwfilter_driver.c

@@ -163,6 +163,15 @@ nwfilterDriverInstallDBusMatches(DBusConnection *sysbus ATTRIBUTE_UNUSED)
 
 #endif /* HAVE_FIREWALLD */
 
+static int
+virNWFilterTriggerRebuildImpl(void *opaque)
+{
+    virNWFilterDriverStatePtr nwdriver = opaque;
+
+    return virNWFilterBuildAll(nwdriver, true);
+}
+
+
 /**
  * nwfilterStateInitialize:
  *
@@ -207,7 +216,7 @@ nwfilterStateInitialize(bool privileged,
     if (virNWFilterTechDriversInit(privileged) < 0)
         goto err_dhcpsnoop_shutdown;
 
-    if (virNWFilterConfLayerInit(virNWFilterDomainFWUpdateCB,
+    if (virNWFilterConfLayerInit(virNWFilterTriggerRebuildImpl,
                                  driver) < 0)
         goto err_techdrivers_shutdown;
 
@@ -302,15 +311,14 @@ nwfilterStateReload(void)
 
     nwfilterDriverLock();
     virNWFilterWriteLockFilterUpdates();
-    virNWFilterCallbackDriversLock();
 
     virNWFilterObjListLoadAllConfigs(driver->nwfilters, driver->configDir);
 
-    virNWFilterCallbackDriversUnlock();
     virNWFilterUnlockFilterUpdates();
-    nwfilterDriverUnlock();
 
-    virNWFilterInstFiltersOnAllVMs();
+    virNWFilterBuildAll(driver, false);
+
+    nwfilterDriverUnlock();
 
     return 0;
 }
@@ -547,7 +555,6 @@ nwfilterDefineXML(virConnectPtr conn,
 
     nwfilterDriverLock();
     virNWFilterWriteLockFilterUpdates();
-    virNWFilterCallbackDriversLock();
 
     if (!(def = virNWFilterDefParseString(xml)))
         goto cleanup;
@@ -572,7 +579,6 @@ nwfilterDefineXML(virConnectPtr conn,
     if (obj)
         virNWFilterObjUnlock(obj);
 
-    virNWFilterCallbackDriversUnlock();
     virNWFilterUnlockFilterUpdates();
     nwfilterDriverUnlock();
     return nwfilter;
@@ -588,7 +594,6 @@ nwfilterUndefine(virNWFilterPtr nwfilter)
 
     nwfilterDriverLock();
     virNWFilterWriteLockFilterUpdates();
-    virNWFilterCallbackDriversLock();
 
     if (!(obj = nwfilterObjFromNWFilter(nwfilter->uuid)))
         goto cleanup;
@@ -615,7 +620,6 @@ nwfilterUndefine(virNWFilterPtr nwfilter)
     if (obj)
         virNWFilterObjUnlock(obj);
 
-    virNWFilterCallbackDriversUnlock();
     virNWFilterUnlockFilterUpdates();
     nwfilterDriverUnlock();
     return ret;

src/nwfilter/nwfilter_gentech_driver.c

@@ -153,9 +153,9 @@ virNWFilterVarHashmapAddStdValues(virHashTablePtr table,
         if (!val)
             return -1;
 
-        if (virHashAddEntry(table,
+        if (virHashUpdateEntry(table,
-                            NWFILTER_STD_VAR_MAC,
+                               NWFILTER_STD_VAR_MAC,
-                            val) < 0) {
+                               val) < 0) {
             virNWFilterVarValueFree(val);
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            "%s", _("Could not add variable 'MAC' to hashmap"));
@@ -168,9 +168,9 @@ virNWFilterVarHashmapAddStdValues(virHashTablePtr table,
         if (!val)
             return -1;
 
-        if (virHashAddEntry(table,
+        if (virHashUpdateEntry(table,
-                            NWFILTER_STD_VAR_IP,
+                               NWFILTER_STD_VAR_IP,
-                            val) < 0) {
+                               val) < 0) {
             virNWFilterVarValueFree(val);
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            "%s", _("Could not add variable 'IP' to hashmap"));
@@ -973,68 +973,113 @@ virNWFilterTeardownFilter(virNWFilterBindingDefPtr binding)
     return ret;
 }
 
+enum {
+    STEP_APPLY_NEW,
+    STEP_ROLLBACK,
+    STEP_SWITCH,
+    STEP_APPLY_CURRENT,
+};
 
-int
+static int
-virNWFilterDomainFWUpdateCB(virDomainObjPtr obj,
+virNWFilterBuildOne(virNWFilterDriverStatePtr driver,
-                            void *data)
+                    virNWFilterBindingDefPtr binding,
+                    virHashTablePtr skipInterfaces,
+                    int step)
 {
-    virDomainDefPtr vm = obj->def;
-    struct domUpdateCBStruct *cb = data;
-    size_t i;
     bool skipIface;
     int ret = 0;
+    VIR_DEBUG("Building filter for portdev=%s step=%d", binding->portdevname, step);
 
-    virObjectLock(obj);
+    switch (step) {
-
+    case STEP_APPLY_NEW:
-    if (virDomainObjIsActive(obj)) {
+        ret = virNWFilterUpdateInstantiateFilter(driver,
-        for (i = 0; i < vm->nnets; i++) {
+                                                 binding,
-            virDomainNetDefPtr net = vm->nets[i];
+                                                 &skipIface);
-            virNWFilterBindingDefPtr binding;
+        if (ret == 0 && skipIface) {
-
+            /* filter tree unchanged -- no update needed */
-            if ((net->filter) && (net->ifname) &&
+            ret = virHashAddEntry(skipInterfaces,
-                (binding = virNWFilterBindingDefForNet(
+                                  binding->portdevname,
-                    vm->name, vm->uuid, net))) {
+                                  (void *)~0);
-
-                switch (cb->step) {
-                case STEP_APPLY_NEW:
-                    ret = virNWFilterUpdateInstantiateFilter(cb->opaque,
-                                                             binding,
-                                                             &skipIface);
-                    if (ret == 0 && skipIface) {
-                        /* filter tree unchanged -- no update needed */
-                        ret = virHashAddEntry(cb->skipInterfaces,
-                                              net->ifname,
-                                              (void *)~0);
-                    }
-                    break;
-
-                case STEP_TEAR_NEW:
-                    if (!virHashLookup(cb->skipInterfaces, net->ifname))
-                        ret = virNWFilterRollbackUpdateFilter(binding);
-                    break;
-
-                case STEP_TEAR_OLD:
-                    if (!virHashLookup(cb->skipInterfaces, net->ifname))
-                        ret = virNWFilterTearOldFilter(binding);
-                    break;
-
-                case STEP_APPLY_CURRENT:
-                    ret = virNWFilterInstantiateFilter(cb->opaque,
-                                                       binding);
-                    if (ret)
-                        virReportError(VIR_ERR_INTERNAL_ERROR,
-                                       _("Failure while applying current filter on "
-                                         "VM %s"), vm->name);
-                    break;
-                }
-                virNWFilterBindingDefFree(binding);
-                if (ret)
-                    break;
-            }
         }
+        break;
+
+    case STEP_ROLLBACK:
+        if (!virHashLookup(skipInterfaces, binding->portdevname))
+            ret = virNWFilterRollbackUpdateFilter(binding);
+        break;
+
+    case STEP_SWITCH:
+        if (!virHashLookup(skipInterfaces, binding->portdevname))
+            ret = virNWFilterTearOldFilter(binding);
+        break;
+
+    case STEP_APPLY_CURRENT:
+        ret = virNWFilterInstantiateFilter(driver,
+                                           binding);
+        break;
     }
 
-    virObjectUnlock(obj);
+    return ret;
+}
+
+
+struct virNWFilterBuildData {
+    virNWFilterDriverStatePtr driver;
+    virHashTablePtr skipInterfaces;
+    int step;
+};
+
+static int
+virNWFilterBuildIter(virNWFilterBindingObjPtr binding, void *opaque)
+{
+    struct virNWFilterBuildData *data = opaque;
+    virNWFilterBindingDefPtr def = virNWFilterBindingObjGetDef(binding);
+
+    return virNWFilterBuildOne(data->driver, def,
+                               data->skipInterfaces, data->step);
+}
+
+int
+virNWFilterBuildAll(virNWFilterDriverStatePtr driver,
+                    bool newFilters)
+{
+    struct virNWFilterBuildData data = {
+        .driver = driver,
+    };
+    int ret = 0;
+
+    VIR_DEBUG("Build all filters newFilters=%d", newFilters);
+
+    if (newFilters) {
+        if (!(data.skipInterfaces = virHashCreate(0, NULL)))
+            return -1;
+
+        data.step = STEP_APPLY_NEW;
+        if (virNWFilterBindingObjListForEach(driver->bindings,
+                                             virNWFilterBuildIter,
+                                             &data) < 0)
+            ret = -1;
+
+        if (ret == -1) {
+            data.step = STEP_ROLLBACK;
+            virNWFilterBindingObjListForEach(driver->bindings,
+                                             virNWFilterBuildIter,
+                                             &data);
+        } else  {
+            data.step = STEP_SWITCH;
+            virNWFilterBindingObjListForEach(driver->bindings,
+                                             virNWFilterBuildIter,
+                                             &data);
+        }
+
+        virHashFree(data.skipInterfaces);
+    } else {
+        data.step = STEP_APPLY_CURRENT;
+        if (virNWFilterBindingObjListForEach(driver->bindings,
+                                             virNWFilterBuildIter,
+                                             &data) < 0)
+            ret = -1;
+    }
     return ret;
 }
 

src/nwfilter/nwfilter_gentech_driver.h

@@ -54,8 +54,8 @@ int virNWFilterTeardownFilter(virNWFilterBindingDefPtr binding);
 virHashTablePtr virNWFilterCreateVarHashmap(const char *macaddr,
                                             const virNWFilterVarValue *value);
 
-int virNWFilterDomainFWUpdateCB(virDomainObjPtr vm,
+int virNWFilterBuildAll(virNWFilterDriverStatePtr driver,
-                                void *data);
+                        bool newFilters);
 
 virNWFilterBindingDefPtr virNWFilterBindingDefForNet(const char *vmname,
                                                      const unsigned char *vmuuid,

src/qemu/qemu_driver.c

@@ -84,7 +84,6 @@
 #include "cpu/cpu.h"
 #include "virsysinfo.h"
 #include "domain_nwfilter.h"
-#include "nwfilter_conf.h"
 #include "virhook.h"
 #include "virstoragefile.h"
 #include "virfile.h"
@@ -164,28 +163,6 @@ static int qemuARPGetInterfaces(virDomainObjPtr vm,
 
 static virQEMUDriverPtr qemu_driver;
 
-
-static void
-qemuVMDriverLock(void)
-{}
-static void
-qemuVMDriverUnlock(void)
-{}
-
-static int
-qemuVMFilterRebuild(virDomainObjListIterator iter, void *data)
-{
-    return virDomainObjListForEach(qemu_driver->domains, iter, data);
-}
-
-static virNWFilterCallbackDriver qemuCallbackDriver = {
-    .name = QEMU_DRIVER_NAME,
-    .vmFilterRebuild = qemuVMFilterRebuild,
-    .vmDriverLock = qemuVMDriverLock,
-    .vmDriverUnlock = qemuVMDriverUnlock,
-};
-
-
 /**
  * qemuDomObjFromDomain:
  * @domain: Domain pointer that has to be looked up
@@ -941,7 +918,6 @@ qemuStateInitialize(bool privileged,
 
     qemuProcessReconnectAll(qemu_driver);
 
-    virNWFilterRegisterCallbackDriver(&qemuCallbackDriver);
     return 0;
 
  error:
@@ -1081,7 +1057,6 @@ qemuStateCleanup(void)
     if (!qemu_driver)
         return -1;
 
-    virNWFilterUnRegisterCallbackDriver(&qemuCallbackDriver);
     virThreadPoolFree(qemu_driver->workerPool);
     virObjectUnref(qemu_driver->config);
     virObjectUnref(qemu_driver->hostdevMgr);

src/uml/uml_driver.c

@@ -55,7 +55,6 @@
 #include "datatypes.h"
 #include "virlog.h"
 #include "domain_nwfilter.h"
-#include "nwfilter_conf.h"
 #include "virfile.h"
 #include "virfdstream.h"
 #include "configmake.h"
@@ -143,25 +142,6 @@ static int umlMonitorCommand(const struct uml_driver *driver,
 
 static struct uml_driver *uml_driver;
 
-static int
-umlVMFilterRebuild(virDomainObjListIterator iter, void *data)
-{
-    return virDomainObjListForEach(uml_driver->domains, iter, data);
-}
-
-static void
-umlVMDriverLock(void)
-{
-    umlDriverLock(uml_driver);
-}
-
-static void
-umlVMDriverUnlock(void)
-{
-    umlDriverUnlock(uml_driver);
-}
-
-
 static virDomainObjPtr
 umlDomObjFromDomainLocked(struct uml_driver *driver,
                           const unsigned char *uuid)
@@ -194,13 +174,6 @@ umlDomObjFromDomain(struct uml_driver *driver,
 }
 
 
-static virNWFilterCallbackDriver umlCallbackDriver = {
-    .name = "UML",
-    .vmFilterRebuild = umlVMFilterRebuild,
-    .vmDriverLock = umlVMDriverLock,
-    .vmDriverUnlock = umlVMDriverUnlock,
-};
-
 struct umlAutostartData {
     struct uml_driver *driver;
     virConnectPtr conn;
@@ -604,7 +577,6 @@ umlStateInitialize(bool privileged,
 
     VIR_FREE(userdir);
 
-    virNWFilterRegisterCallbackDriver(&umlCallbackDriver);
     return 0;
 
  out_of_memory:
@@ -697,7 +669,6 @@ umlStateCleanup(void)
         return -1;
 
     umlDriverLock(uml_driver);
-    virNWFilterRegisterCallbackDriver(&umlCallbackDriver);
     if (uml_driver->inotifyWatch != -1)
         virEventRemoveHandle(uml_driver->inotifyWatch);
     VIR_FORCE_CLOSE(uml_driver->inotifyFD);