Commit 410f0383 authored Sep 02, 2015 by Marcelo Ricardo Leitner Committed by David S. Miller Sep 03, 2015

sctp: add routing output fallback



Commit 0ca50d12 added a restriction that the address must belong to
the output interface, so that sctp will use the right interface even
when using secondary addresses.

But it breaks IPVS setups, on which people is used to attach VIP
addresses to loopback interface on real servers. It's preferred to
attach to the interface actually in use, but it's a very common setup
and that used to work.

This patch then saves the first routing good result, even if it would be
going out through an interface that doesn't have that address. If no
better hit found, it's then used. This effectively restores the original
behavior if no better interface could be found.

Fixes: 0ca50d12 ("sctp: fix src address selection if using secondary addresses")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d82f0f1f

net/sctp/protocol.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -506,16 +506,22 @@ static void sctp_v4_get_dst(struct sctp_transport t, union sctp_addr saddr,
		if (IS_ERR(rt))
		continue;

		if (!dst)
		dst = &rt->dst;

		/* Ensure the src address belongs to the output
		* interface.
		*/
		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
		false);
		if (!odev \|\| odev->ifindex != fl4->flowi4_oif) {
		if (&rt->dst != dst)
		dst_release(&rt->dst);
		continue;
		}

		if (dst != &rt->dst)
		dst_release(dst);
		dst = &rt->dst;
		break;
		}

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