Function read_outblob_with_retry

tdx-attest/src/linux.rs:454–494

(path: &str)

}

fn read_outblob_with_retry(path: &str) -> Result<Vec<u8>> {
    const RETRY_WAIT_MS: u64 = 10000;
    const MAX_RETRIES: usize = 3;

    let mut last_err = None;
    for _ in 0..MAX_RETRIES {
        let mut file = match File::open(path) {
            Ok(f) => f,
            Err(e) => {
                last_err = Some(e);
                continue;
            }
        };

        let mut buf = vec![0u8; QUOTE_BUF_SIZE];
        match file.read(&mut buf) {
            Ok(n) if n > 0 => {
                buf.truncate(n);
                return Ok(buf);
            }
            Ok(_) => {
                return Err(TdxAttestError::QuoteFailure("empty outblob".to_string()));
            }
            Err(e) => {
                let errno = e.raw_os_error().unwrap_or(0);
                if errno == libc::EBUSY || errno == libc::EINTR || errno == libc::ETIMEDOUT {
                    thread::sleep(Duration::from_millis(RETRY_WAIT_MS));
                    last_err = Some(e);
                    continue;
                }
                return Err(TdxAttestError::QuoteFailure(format!("read {path}: {e}")));
            }
        }
    }

    match last_err {
        Some(e) if e.raw_os_error() == Some(libc::EBUSY) => Err(TdxAttestError::Busy),
        Some(e) => Err(TdxAttestError::QuoteFailure(format!("read {path}: {e}"))),
        None => Err(TdxAttestError::Unexpected("unknown error".to_string())),
    }
}

// ============================================================================
// VSock Quote Generation (QGS Protocol)