util/uuid: Add UUID_STR_LEN definition

qemu_uuid_unparse() includes a trailing NUL when writing the uuid
string and the buffer size should be UUID_FMT_LEN + 1 bytes. Add a
define for this size and use it where required.

Cc: Fam Zheng <fam@euphon.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: "Denis V. Lunev" <den@openvz.org>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

block/parallels-ext.c

@@ -130,7 +130,7 @@ static BdrvDirtyBitmap *parallels_load_bitmap(BlockDriverState *bs,
     g_autofree uint64_t *l1_table = NULL;
     BdrvDirtyBitmap *bitmap;
     QemuUUID uuid;
-    char uuidstr[UUID_FMT_LEN + 1];
+    char uuidstr[UUID_STR_LEN];
     int i;
 
     if (data_size < sizeof(bf)) {

block/vdi.c

@@ -239,7 +239,7 @@ static void vdi_header_to_le(VdiHeader *header)
 
 static void vdi_header_print(VdiHeader *header)
 {
-    char uuidstr[37];
+    char uuidstr[UUID_STR_LEN];
     QemuUUID uuid;
     logout("text        %s", header->text);
     logout("signature   0x%08x\n", header->signature);

hw/core/qdev-properties-system.c

@@ -1114,7 +1114,7 @@ static void get_uuid(Object *obj, Visitor *v, const char *name, void *opaque,
 {
     Property *prop = opaque;
     QemuUUID *uuid = object_field_prop_ptr(obj, prop);
-    char buffer[UUID_FMT_LEN + 1];
+    char buffer[UUID_STR_LEN];
     char *p = buffer;
 
     qemu_uuid_unparse(uuid, buffer);

hw/hyperv/vmbus.c

@@ -2271,7 +2271,7 @@ static void vmbus_dev_realize(DeviceState *dev, Error **errp)
     VMBus *vmbus = VMBUS(qdev_get_parent_bus(dev));
     BusChild *child;
     Error *err = NULL;
-    char idstr[UUID_FMT_LEN + 1];
+    char idstr[UUID_STR_LEN];
 
     assert(!qemu_uuid_is_null(&vdev->instanceid));
 
@@ -2467,7 +2467,7 @@ static char *vmbus_get_dev_path(DeviceState *dev)
 static char *vmbus_get_fw_dev_path(DeviceState *dev)
 {
     VMBusDevice *vdev = VMBUS_DEVICE(dev);
-    char uuid[UUID_FMT_LEN + 1];
+    char uuid[UUID_STR_LEN];
 
     qemu_uuid_unparse(&vdev->instanceid, uuid);
     return g_strdup_printf("%s@%s", qdev_fw_name(dev), uuid);

include/qemu/uuid.h

@@ -79,6 +79,7 @@ typedef struct {
                  "%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
 #define UUID_FMT_LEN 36
+#define UUID_STR_LEN (UUID_FMT_LEN + 1)
 
 #define UUID_NONE "00000000-0000-0000-0000-000000000000"
 

migration/savevm.c

@@ -471,8 +471,8 @@ static bool vmstate_uuid_needed(void *opaque)
 static int vmstate_uuid_post_load(void *opaque, int version_id)
 {
     SaveState *state = opaque;
-    char uuid_src[UUID_FMT_LEN + 1];
-    char uuid_dst[UUID_FMT_LEN + 1];
+    char uuid_src[UUID_STR_LEN];
+    char uuid_dst[UUID_STR_LEN];
 
     if (!qemu_uuid_set) {
         /*

tests/unit/test-uuid.c

@@ -145,7 +145,7 @@ static void test_uuid_unparse(void)
     int i;
 
     for (i = 0; i < ARRAY_SIZE(uuid_test_data); i++) {
-        char out[37];
+        char out[UUID_STR_LEN];
 
         if (!uuid_test_data[i].check_unparse) {
             continue;

util/uuid.c

@@ -51,7 +51,7 @@ int qemu_uuid_is_equal(const QemuUUID *lhv, const QemuUUID *rhv)
 void qemu_uuid_unparse(const QemuUUID *uuid, char *out)
 {
     const unsigned char *uu = &uuid->data[0];
-    snprintf(out, UUID_FMT_LEN + 1, UUID_FMT,
+    snprintf(out, UUID_STR_LEN, UUID_FMT,
              uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
              uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]);
 }