Remove use of virConnectPtr from all remaining nwfilter code

The virConnectPtr is passed around loads of nwfilter code in
order to provide it as a parameter to the callback registered
by the virt drivers. None of the virt drivers use this param
though, so it serves no purpose.

Avoiding the need to pass a virConnectPtr means that the
nwfilterStateReload method no longer needs to open a bogus
QEMU driver connection. This addresses a race condition that
can lead to a crash on startup.

The nwfilter driver starts before the QEMU driver and registers
some callbacks with DBus to detect firewalld reload. If the
firewalld reload happens while the QEMU driver is still starting
up though, the nwfilterStateReload method will open a connection
to the partially initialized QEMU driver and cause a crash.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/conf/nwfilter_conf.c

@@ -2744,8 +2744,7 @@ cleanup:
 
 
 static int
-_virNWFilterDefLoopDetect(virConnectPtr conn,
-                          virNWFilterObjListPtr nwfilters,
+_virNWFilterDefLoopDetect(virNWFilterObjListPtr nwfilters,
                           virNWFilterDefPtr def,
                           const char *filtername)
 {
@@ -2769,7 +2768,7 @@ _virNWFilterDefLoopDetect(virConnectPtr conn,
             obj = virNWFilterObjFindByName(nwfilters,
                                            entry->include->filterref);
             if (obj) {
-                rc = _virNWFilterDefLoopDetect(conn, nwfilters,
+                rc = _virNWFilterDefLoopDetect(nwfilters,
                                                obj->def, filtername);
 
                 virNWFilterObjUnlock(obj);
@@ -2785,7 +2784,6 @@ _virNWFilterDefLoopDetect(virConnectPtr conn,
 
 /*
  * virNWFilterDefLoopDetect:
- * @conn: pointer to virConnect object
  * @nwfilters : the nwfilters to search
  * @def : the filter definition that may add a loop and is to be tested
  *
@@ -2795,11 +2793,10 @@ _virNWFilterDefLoopDetect(virConnectPtr conn,
  * Returns 0 in case no loop was detected, -1 otherwise.
  */
 static int
-virNWFilterDefLoopDetect(virConnectPtr conn,
-                         virNWFilterObjListPtr nwfilters,
+virNWFilterDefLoopDetect(virNWFilterObjListPtr nwfilters,
                          virNWFilterDefPtr def)
 {
-    return _virNWFilterDefLoopDetect(conn, nwfilters, def, def->name);
+    return _virNWFilterDefLoopDetect(nwfilters, def, def->name);
 }
 
 int nCallbackDriver;
@@ -2858,7 +2855,7 @@ static void *virNWFilterDomainFWUpdateOpaque;
  * error. This should be called upon reloading of the driver.
  */
 int
-virNWFilterInstFiltersOnAllVMs(virConnectPtr conn)
+virNWFilterInstFiltersOnAllVMs(void)
 {
     size_t i;
     struct domUpdateCBStruct cb = {
@@ -2868,15 +2865,14 @@ virNWFilterInstFiltersOnAllVMs(virConnectPtr conn)
     };
 
     for (i = 0; i < nCallbackDriver; i++)
-        callbackDrvArray[i]->vmFilterRebuild(conn,
-                                             virNWFilterDomainFWUpdateCB,
+        callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
                                              &cb);
 
     return 0;
 }
 
 static int
-virNWFilterTriggerVMFilterRebuild(virConnectPtr conn)
+virNWFilterTriggerVMFilterRebuild(void)
 {
     size_t i;
     int ret = 0;
@@ -2890,8 +2886,7 @@ virNWFilterTriggerVMFilterRebuild(virConnectPtr conn)
         return -1;
 
     for (i = 0; i < nCallbackDriver; i++) {
-        if (callbackDrvArray[i]->vmFilterRebuild(conn,
-                                                 virNWFilterDomainFWUpdateCB,
+        if (callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
                                                  &cb) < 0)
             ret = -1;
     }
@@ -2900,15 +2895,13 @@ virNWFilterTriggerVMFilterRebuild(virConnectPtr conn)
         cb.step = STEP_TEAR_NEW; /* rollback */
 
         for (i = 0; i < nCallbackDriver; i++)
-            callbackDrvArray[i]->vmFilterRebuild(conn,
-                                                 virNWFilterDomainFWUpdateCB,
+            callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
                                                  &cb);
     } else {
         cb.step = STEP_TEAR_OLD; /* switch over */
 
         for (i = 0; i < nCallbackDriver; i++)
-            callbackDrvArray[i]->vmFilterRebuild(conn,
-                                                 virNWFilterDomainFWUpdateCB,
+            callbackDrvArray[i]->vmFilterRebuild(virNWFilterDomainFWUpdateCB,
                                                  &cb);
     }
 
@@ -2919,14 +2912,13 @@ virNWFilterTriggerVMFilterRebuild(virConnectPtr conn)
 
 
 int
-virNWFilterTestUnassignDef(virConnectPtr conn,
-                           virNWFilterObjPtr nwfilter)
+virNWFilterTestUnassignDef(virNWFilterObjPtr nwfilter)
 {
     int rc = 0;
 
     nwfilter->wantRemoved = 1;
     /* trigger the update on VMs referencing the filter */
-    if (virNWFilterTriggerVMFilterRebuild(conn))
+    if (virNWFilterTriggerVMFilterRebuild())
         rc = -1;
 
     nwfilter->wantRemoved = 0;
@@ -2965,8 +2957,7 @@ cleanup:
 }
 
 virNWFilterObjPtr
-virNWFilterObjAssignDef(virConnectPtr conn,
-                        virNWFilterObjListPtr nwfilters,
+virNWFilterObjAssignDef(virNWFilterObjListPtr nwfilters,
                         virNWFilterDefPtr def)
 {
     virNWFilterObjPtr nwfilter;
@@ -2985,7 +2976,7 @@ virNWFilterObjAssignDef(virConnectPtr conn,
         virNWFilterObjUnlock(nwfilter);
     }
 
-    if (virNWFilterDefLoopDetect(conn, nwfilters, def) < 0) {
+    if (virNWFilterDefLoopDetect(nwfilters, def) < 0) {
         virReportError(VIR_ERR_OPERATION_FAILED,
                        "%s", _("filter would introduce a loop"));
         return NULL;
@@ -3004,7 +2995,7 @@ virNWFilterObjAssignDef(virConnectPtr conn,
 
         nwfilter->newDef = def;
         /* trigger the update on VMs referencing the filter */
-        if (virNWFilterTriggerVMFilterRebuild(conn)) {
+        if (virNWFilterTriggerVMFilterRebuild()) {
             nwfilter->newDef = NULL;
             virNWFilterUnlockFilterUpdates();
             virNWFilterObjUnlock(nwfilter);
@@ -3046,8 +3037,7 @@ virNWFilterObjAssignDef(virConnectPtr conn,
 
 
 static virNWFilterObjPtr
-virNWFilterObjLoad(virConnectPtr conn,
-                   virNWFilterObjListPtr nwfilters,
+virNWFilterObjLoad(virNWFilterObjListPtr nwfilters,
                    const char *file,
                    const char *path)
 {
@@ -3066,7 +3056,7 @@ virNWFilterObjLoad(virConnectPtr conn,
         return NULL;
     }
 
-    if (!(nwfilter = virNWFilterObjAssignDef(conn, nwfilters, def))) {
+    if (!(nwfilter = virNWFilterObjAssignDef(nwfilters, def))) {
         virNWFilterDefFree(def);
         return NULL;
     }
@@ -3082,8 +3072,7 @@ virNWFilterObjLoad(virConnectPtr conn,
 
 
 int
-virNWFilterLoadAllConfigs(virConnectPtr conn,
-                          virNWFilterObjListPtr nwfilters,
+virNWFilterLoadAllConfigs(virNWFilterObjListPtr nwfilters,
                           const char *configDir)
 {
     DIR *dir;
@@ -3111,7 +3100,7 @@ virNWFilterLoadAllConfigs(virConnectPtr conn,
         if (!(path = virFileBuildPath(configDir, entry->d_name, NULL)))
             continue;
 
-        nwfilter = virNWFilterObjLoad(conn, nwfilters, entry->d_name, path);
+        nwfilter = virNWFilterObjLoad(nwfilters, entry->d_name, path);
         if (nwfilter)
             virNWFilterObjUnlock(nwfilter);
 

src/conf/nwfilter_conf.h

@@ -687,12 +687,10 @@ int virNWFilterObjSaveDef(virNWFilterDriverStatePtr driver,
 
 int virNWFilterObjDeleteDef(virNWFilterObjPtr nwfilter);
 
-virNWFilterObjPtr virNWFilterObjAssignDef(virConnectPtr conn,
-                                          virNWFilterObjListPtr nwfilters,
+virNWFilterObjPtr virNWFilterObjAssignDef(virNWFilterObjListPtr nwfilters,
                                           virNWFilterDefPtr def);
 
-int virNWFilterTestUnassignDef(virConnectPtr conn,
-                               virNWFilterObjPtr nwfilter);
+int virNWFilterTestUnassignDef(virNWFilterObjPtr nwfilter);
 
 virNWFilterDefPtr virNWFilterDefParseNode(xmlDocPtr xml,
                                           xmlNodePtr root);
@@ -706,8 +704,7 @@ int virNWFilterSaveXML(const char *configDir,
 int virNWFilterSaveConfig(const char *configDir,
                           virNWFilterDefPtr def);
 
-int virNWFilterLoadAllConfigs(virConnectPtr conn,
-                              virNWFilterObjListPtr nwfilters,
+int virNWFilterLoadAllConfigs(virNWFilterObjListPtr nwfilters,
                               const char *configDir);
 
 char *virNWFilterConfigFile(const char *dir,
@@ -725,11 +722,10 @@ void virNWFilterUnlockFilterUpdates(void);
 int virNWFilterConfLayerInit(virDomainObjListIterator domUpdateCB, void *opaque);
 void virNWFilterConfLayerShutdown(void);
 
-int virNWFilterInstFiltersOnAllVMs(virConnectPtr conn);
+int virNWFilterInstFiltersOnAllVMs(void);
 
 
-typedef int (*virNWFilterRebuild)(virConnectPtr conn,
-                                  virDomainObjListIterator domUpdateCB,
+typedef int (*virNWFilterRebuild)(virDomainObjListIterator domUpdateCB,
                                   void *data);
 typedef void (*virNWFilterVoidCall)(void);
 

src/lxc/lxc_driver.c

@@ -84,8 +84,7 @@ virLXCDriverPtr lxc_driver = NULL;
 
 /* callbacks for nwfilter */
 static int
-lxcVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED,
-                   virDomainObjListIterator iter, void *data)
+lxcVMFilterRebuild(virDomainObjListIterator iter, void *data)
 {
     return virDomainObjListForEach(lxc_driver->domains, iter, data);
 }

src/nwfilter/nwfilter_driver.c

@@ -235,8 +235,7 @@ nwfilterStateInitialize(bool privileged,
 
     VIR_FREE(base);
 
-    if (virNWFilterLoadAllConfigs(NULL,
-                                  &driverState->nwfilters,
+    if (virNWFilterLoadAllConfigs(&driverState->nwfilters,
                                   driverState->configDir) < 0)
         goto error;
 
@@ -272,37 +271,28 @@ err_free_driverstate:
  * files and update its state
  */
 static int
-nwfilterStateReload(void) {
-    virConnectPtr conn;
-
-    if (!driverState) {
+nwfilterStateReload(void)
+{
+    if (!driverState)
         return -1;
-    }
 
     if (!driverState->privileged)
         return 0;
 
-    conn = virConnectOpen("qemu:///system");
-
-    if (conn) {
-        virNWFilterDHCPSnoopEnd(NULL);
-        /* shut down all threads -- they will be restarted if necessary */
-        virNWFilterLearnThreadsTerminate(true);
-
-        nwfilterDriverLock(driverState);
-        virNWFilterCallbackDriversLock();
+    virNWFilterDHCPSnoopEnd(NULL);
+    /* shut down all threads -- they will be restarted if necessary */
+    virNWFilterLearnThreadsTerminate(true);
 
-        virNWFilterLoadAllConfigs(conn,
-                                  &driverState->nwfilters,
-                                  driverState->configDir);
+    nwfilterDriverLock(driverState);
+    virNWFilterCallbackDriversLock();
 
-        virNWFilterCallbackDriversUnlock();
-        nwfilterDriverUnlock(driverState);
+    virNWFilterLoadAllConfigs(&driverState->nwfilters,
+                              driverState->configDir);
 
-        virNWFilterInstFiltersOnAllVMs(conn);
+    virNWFilterCallbackDriversUnlock();
+    nwfilterDriverUnlock(driverState);
 
-        virConnectClose(conn);
-    }
+    virNWFilterInstFiltersOnAllVMs();
 
     return 0;
 }
@@ -573,7 +563,7 @@ nwfilterDefineXML(virConnectPtr conn,
     if (virNWFilterDefineXMLEnsureACL(conn, def) < 0)
         goto cleanup;
 
-    if (!(nwfilter = virNWFilterObjAssignDef(conn, &driver->nwfilters, def)))
+    if (!(nwfilter = virNWFilterObjAssignDef(&driver->nwfilters, def)))
         goto cleanup;
 
     if (virNWFilterObjSaveDef(driver, nwfilter, def) < 0) {
@@ -617,7 +607,7 @@ nwfilterUndefine(virNWFilterPtr obj) {
     if (virNWFilterUndefineEnsureACL(obj->conn, nwfilter->def) < 0)
         goto cleanup;
 
-    if (virNWFilterTestUnassignDef(obj->conn, nwfilter) < 0) {
+    if (virNWFilterTestUnassignDef(nwfilter) < 0) {
         virReportError(VIR_ERR_OPERATION_INVALID,
                        "%s",
                        _("nwfilter is in use"));

src/qemu/qemu_driver.c

@@ -177,8 +177,7 @@ static void
 qemuVMDriverUnlock(void) {}
 
 static int
-qemuVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED,
-                    virDomainObjListIterator iter, void *data)
+qemuVMFilterRebuild(virDomainObjListIterator iter, void *data)
 {
     return virDomainObjListForEach(qemu_driver->domains, iter, data);
 }

src/uml/uml_driver.c

@@ -148,8 +148,7 @@ static int umlMonitorCommand(const struct uml_driver *driver,
 static struct uml_driver *uml_driver = NULL;
 
 static int
-umlVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED,
-                   virDomainObjListIterator iter, void *data)
+umlVMFilterRebuild(virDomainObjListIterator iter, void *data)
 {
     return virDomainObjListForEach(uml_driver->domains, iter, data);
 }