fn parse_enclave_cid()

in src/common/commands_parser.rs [380:449]

• 54 lines of code
• 8 McCabe index (conditional complexity)

fn parse_enclave_cid(args: &ArgMatches) -> NitroCliResult<Option<u64>> {
    let enclave_cid = if let Some(enclave_cid) = args.get_one::<String>("enclave-cid") {
        let enclave_cid: u64 = enclave_cid.parse().map_err(|_| {
            new_nitro_cli_failure!(
                "`enclave-cid` is not a number",
                NitroCliErrorEnum::InvalidArgument
            )
            .add_info(vec!["enclave-cid", enclave_cid])
        })?;

        // Do not use well-known CID values - 0, 1, 2 - as the enclave CID.
        // VMADDR_CID_ANY = -1U
        // VMADDR_CID_HYPERVISOR = 0
        // VMADDR_CID_LOCAL = 1
        // VMADDR_CID_HOST = 2
        // Note: 0 is used as a placeholder to auto-generate a CID.
        // <http://man7.org/linux/man-pages/man7/vsock.7.html>
        if enclave_cid == 0 {
            eprintln!("The enclave CID will be auto-generated as the provided CID is 0");
        }

        if enclave_cid > 0 && enclave_cid <= VMADDR_CID_HOST as u64 {
            return Err(new_nitro_cli_failure!(
                &format!(
                    "CID {} is a well-known CID, not to be used for enclaves",
                    enclave_cid
                ),
                NitroCliErrorEnum::InvalidArgument
            ));
        }

        if enclave_cid == u32::MAX as u64 {
            return Err(new_nitro_cli_failure!(
                &format!(
                    "CID {} is a well-known CID, not to be used for enclaves",
                    enclave_cid
                ),
                NitroCliErrorEnum::InvalidArgument
            ));
        }

        // Do not use the CID of the parent VM as the enclave CID.
        if enclave_cid == VMADDR_CID_PARENT as u64 {
            return Err(new_nitro_cli_failure!(
                &format!(
                    "CID {} is the CID of the parent VM, not to be used for enclaves",
                    enclave_cid
                ),
                NitroCliErrorEnum::InvalidArgument
            ));
        }

        // 64-bit CIDs are not yet supported for the vsock device.
        if enclave_cid > u32::MAX as u64 {
            return Err(new_nitro_cli_failure!(
                &format!(
                    "CID {} is higher than the maximum supported (u32 max) for a vsock device",
                    enclave_cid
                ),
                NitroCliErrorEnum::InvalidArgument
            ));
        }

        Some(enclave_cid)
    } else {
        None
    };

    Ok(enclave_cid)
}