SMB_USER_MAGIC
user->u_magic = SMB_USER_MAGIC;
ASSERT(user->u_magic == SMB_USER_MAGIC);
ASSERT(user->u_magic == SMB_USER_MAGIC);
ASSERT(user->u_magic == SMB_USER_MAGIC);
user->u_magic = (uint32_t)~SMB_USER_MAGIC;
ASSERT(((u) != NULL) && ((u)->u_magic == SMB_USER_MAGIC))