Commit f7b86bfe authored Oct 18, 2012 by Pavel Emelyanov Committed by David S. Miller Oct 21, 2012

sockopt: Make SO_BINDTODEVICE readable

The SO_BINDTODEVICE option is the only SOL_SOCKET one that can be set, but
cannot be get via sockopt API. The only way we can find the device id a
socket is bound to is via sock-diag interface. But the diag works only on
hashed sockets, while the opt in question can be set for yet unhashed one.

That said, in order to know what device a socket is bound to (we do want
to know this in checkpoint-restore project) I propose to make this option
getsockopt-able and report the respective device index.

Another solution to the problem might be to teach the sock-diag reporting
info on unhashed sockets. Should I go this way instead?

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0da5f7c6

net/core/sock.c

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1074,6 +1074,9 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
	case SO_NOFCS:		case SO_NOFCS:
	v.val = sock_flag(sk, SOCK_NOFCS);		v.val = sock_flag(sk, SOCK_NOFCS);
	break;		break;
			case SO_BINDTODEVICE:
			v.val = sk->sk_bound_dev_if;
			break;
	default:		default:
	return -ENOPROTOOPT;		return -ENOPROTOOPT;
	}		}

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