maint: improve VIR_ERR_INVALID_INTERFACE usage

When checking for a valid interface, we weren't consistent on
whether we reported as VIR_FROM_NONE or VIR_FROM_INTERFACE.
Similar to previous patches, use a common macro to make it nicer.
Furthermore, just as in commit 6e130ddc, the difference between
VIR_IS_INTERFACE and VIR_IS_CONNECTED_INTERFACE is moot (due to
reference counting, any valid interface must be tied to a valid
connection).  For now, we don't need virCheckInterfaceGoto().

* src/datatypes.h (virCheckInterfaceReturn): New macro.
(VIR_IS_INTERFACE, VIR_IS_CONNECTED_INTERFACE): Drop unused
macros.
* src/libvirt.c: Use macro throughout.
(virLibInterfaceError): Drop unused macro.
Signed-off-by: NEric Blake <eblake@redhat.com>

src/datatypes.h

@@ -110,10 +110,19 @@ extern virClassPtr virStoragePoolClass;
         }                                                               \
     } while (0)
 
-# define VIR_IS_INTERFACE(obj) \
-    (virObjectIsClass((obj), virInterfaceClass))
-# define VIR_IS_CONNECTED_INTERFACE(obj) \
-    (VIR_IS_INTERFACE(obj) && virObjectIsClass((obj)->conn, virConnectClass))
+# define virCheckInterfaceReturn(obj, retval)                           \
+    do {                                                                \
+        virInterfacePtr _iface = (obj);                                 \
+        if (!virObjectIsClass(_iface, virInterfaceClass) ||             \
+            !virObjectIsClass(_iface->conn, virConnectClass)) {         \
+            virReportErrorHelper(VIR_FROM_INTERFACE,                    \
+                                 VIR_ERR_INVALID_INTERFACE,             \
+                                 __FILE__, __FUNCTION__, __LINE__,      \
+                                 __FUNCTION__);                         \
+            virDispatchError(NULL);                                     \
+            return retval;                                              \
+        }                                                               \
+    } while (0)
 
 # define VIR_IS_STORAGE_POOL(obj) \
     (virObjectIsClass((obj), virStoragePoolClass))

src/libvirt.c

@@ -534,9 +534,6 @@ DllMain(HINSTANCE instance ATTRIBUTE_UNUSED,
 #define virLibStorageVolError(code, ...)                          \
     virReportErrorHelper(VIR_FROM_STORAGE, code, __FILE__,        \
                          __FUNCTION__, __LINE__, __VA_ARGS__)
-#define virLibInterfaceError(code, ...)                           \
-    virReportErrorHelper(VIR_FROM_INTERFACE, code, __FILE__,      \
-                         __FUNCTION__, __LINE__, __VA_ARGS__)
 #define virLibNodeDeviceError(code, ...)                          \
     virReportErrorHelper(VIR_FROM_NODEDEV, code, __FILE__,        \
                          __FUNCTION__, __LINE__, __VA_ARGS__)
@@ -11419,11 +11416,8 @@ virInterfaceGetConnect(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return NULL;
-    }
+    virCheckInterfaceReturn(iface, NULL);
+
     return iface->conn;
 }
 
@@ -11730,11 +11724,8 @@ virInterfaceGetName(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return NULL;
-    }
+    virCheckInterfaceReturn(iface, NULL);
+
     return iface->name;
 }
 
@@ -11757,11 +11748,8 @@ virInterfaceGetMACString(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return NULL;
-    }
+    virCheckInterfaceReturn(iface, NULL);
+
     return iface->mac;
 }
 
@@ -11792,12 +11780,7 @@ virInterfaceGetXMLDesc(virInterfacePtr iface, unsigned int flags)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return NULL;
-    }
-
+    virCheckInterfaceReturn(iface, NULL);
     conn = iface->conn;
 
     if (conn->interfaceDriver && conn->interfaceDriver->interfaceGetXMLDesc) {
@@ -11890,12 +11873,9 @@ virInterfaceUndefine(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
+    virCheckInterfaceReturn(iface, -1);
     conn = iface->conn;
+
     virCheckReadOnlyGoto(conn->flags, error);
 
     if (conn->interfaceDriver && conn->interfaceDriver->interfaceUndefine) {
@@ -11936,12 +11916,9 @@ virInterfaceCreate(virInterfacePtr iface, unsigned int flags)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
+    virCheckInterfaceReturn(iface, -1);
     conn = iface->conn;
+
     virCheckReadOnlyGoto(conn->flags, error);
 
     if (conn->interfaceDriver && conn->interfaceDriver->interfaceCreate) {
@@ -11986,13 +11963,9 @@ virInterfaceDestroy(virInterfacePtr iface, unsigned int flags)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
-
+    virCheckInterfaceReturn(iface, -1);
     conn = iface->conn;
+
     virCheckReadOnlyGoto(conn->flags, error);
 
     if (conn->interfaceDriver && conn->interfaceDriver->interfaceDestroy) {
@@ -12035,11 +12008,8 @@ virInterfaceRef(virInterfacePtr iface)
 
     virResetLastError();
 
-    if ((!VIR_IS_CONNECTED_INTERFACE(iface))) {
-        virLibConnError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
+    virCheckInterfaceReturn(iface, -1);
+
     virObjectRef(iface);
     return 0;
 }
@@ -12061,11 +12031,8 @@ virInterfaceFree(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibInterfaceError(VIR_ERR_INVALID_INTERFACE, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
+    virCheckInterfaceReturn(iface, -1);
+
     virObjectUnref(iface);
     return 0;
 }
@@ -17354,11 +17321,8 @@ virInterfaceIsActive(virInterfacePtr iface)
 
     virResetLastError();
 
-    if (!VIR_IS_CONNECTED_INTERFACE(iface)) {
-        virLibConnError(VIR_ERR_INVALID_CONN, __FUNCTION__);
-        virDispatchError(NULL);
-        return -1;
-    }
+    virCheckInterfaceReturn(iface, -1);
+
     if (iface->conn->interfaceDriver->interfaceIsActive) {
         int ret;
         ret = iface->conn->interfaceDriver->interfaceIsActive(iface);