Function validate_bdf

crates/openshell-vfio/src/sysfs.rs:165–195

Validate a PCI BDF address (format `DDDD:BB:DD.F`).

(bdf: &str)

/// Validate a PCI BDF address (format `DDDD:BB:DD.F`).
pub fn validate_bdf(bdf: &str) -> Result<(), VfioError> {
    let bytes = bdf.as_bytes();
    if bytes.len() != 12 {
        return Err(VfioError::InvalidBdf {
            bdf: bdf.to_string(),
        });
    }

    // Expected layout: [hex x 4]:[hex x 2]:[hex x 2].[hex x 1]
    //                   0123     4 56     7 89     A B
    let ok = is_hex(bytes[0])
        && is_hex(bytes[1])
        && is_hex(bytes[2])
        && is_hex(bytes[3])
        && bytes[4] == b':'
        && is_hex(bytes[5])
        && is_hex(bytes[6])
        && bytes[7] == b':'
        && is_hex(bytes[8])
        && is_hex(bytes[9])
        && bytes[10] == b'.'
        && is_hex(bytes[11]);

    if ok {
        Ok(())
    } else {
        Err(VfioError::InvalidBdf {
            bdf: bdf.to_string(),
        })
    }
}

fn is_hex(b: u8) -> bool {
    b.is_ascii_hexdigit()