Function tap_device_name

crates/openshell-driver-vm/src/gpu.rs:253–262

TAP device name from sandbox ID (fits `IFNAMSIZ=16`).

(sandbox_id: &str)

/// TAP device name from sandbox ID (fits `IFNAMSIZ=16`).
pub fn tap_device_name(sandbox_id: &str) -> String {
    let mut end = sandbox_id.len().min(8);
    // Walk back to a UTF-8 char boundary (str::floor_char_boundary requires
    // Rust 1.91 — we still build on older toolchains).
    while end > 0 && !sandbox_id.is_char_boundary(end) {
        end -= 1;
    }
    let prefix = &sandbox_id[..end];
    format!("vmtap-{prefix}")
}

#[cfg(test)]
mod tests {