//go:build !darwin

package main

import (
	"context"
	"fmt"
	"net"
)

// Everywhere except macOS, interface binding is not the answer to anything this command has met, so asking
// for it is refused rather than silently ignored. A silent no op would let an operator set the variable on
// the Linux node, watch nothing change, and conclude the setting does not work anywhere.
//
// Linux has SO_BINDTODEVICE for the same purpose and it needs CAP_NET_RAW, so if a Linux node ever grows
// the same scoped route problem this is the file that gains the implementation.
func bindToInterface(name string) (func(ctx context.Context, network, addr string) (net.Conn, error), error) {
	if name == "" {
		return nil, nil
	}
	return nil, fmt.Errorf("binding a socket to interface %q is implemented for macOS only on this command", name)
}