buffer_read
len = buffer_read(&in_buffer, dataptr, length);
len = buffer_read(&in_buffer, dataptr, length);
len = buffer_read(&in_buffer, dataptr, length);
len = buffer_read(&in_buffer, dataptr, length);
static int buffer_read(BIO *h, char *buf, int size);
buffer_read,
(void)buffer_read(b, fake_buf, 0);