Function binary_path

crates/openshell-supervisor-network/src/procfs.rs:84–114

(pid: i32)

/// to read `/proc/<pid>/exe` (e.g. same user, or `CAP_SYS_PTRACE`).
#[cfg(target_os = "linux")]
pub fn binary_path(pid: i32) -> Result<PathBuf> {
    use std::ffi::OsString;
    use std::io::ErrorKind;
    use std::os::unix::ffi::{OsStrExt, OsStringExt};

    const DELETED_SUFFIX: &[u8] = b" (deleted)";

    let link = format!("/proc/{pid}/exe");
    let target = std::fs::read_link(&link).map_err(|e| {
        miette::miette!(
            "Failed to read /proc/{pid}/exe: {e}. \
             Cannot determine binary identity — denying request. \
             Hint: the proxy may need CAP_SYS_PTRACE or to run as the same user."
        )
    })?;

    // Only strip when the raw readlink target cannot be stat'd and its bytes
    // end with the kernel-added suffix. This preserves live executables whose
    // basename legitimately ends with " (deleted)" and handles non-UTF-8
    // filenames correctly.
    let raw_target_missing =
        matches!(std::fs::metadata(&target), Err(err) if err.kind() == ErrorKind::NotFound);

    let bytes = target.as_os_str().as_bytes();
    if raw_target_missing && bytes.ends_with(DELETED_SUFFIX) {
        let stripped = bytes[..bytes.len() - DELETED_SUFFIX.len()].to_vec();
        return Ok(PathBuf::from(OsString::from_vec(stripped)));
    }

    Ok(target)
}

/// Resolve the binary path of the TCP peer inside a sandbox network namespace.
///