From 4953f0fcc06a125f87874743d968c0e185c8b296 Mon Sep 17 00:00:00 2001 From: Brian Haley Date: Thu, 11 Oct 2007 14:39:29 -0700 Subject: [PATCH] [IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2 From RFC 3493, Section 5.2: IPV6_MULTICAST_IF Set the interface to use for outgoing multicast packets. The argument is the index of the interface to use. If the interface index is specified as zero, the system selects the interface (for example, by looking up the address in a routing table and using the resulting interface). This patch adds support for (index == 0) to reset the value to it's original state, allowing the system to choose the best interface. IPv4 already behaves this way. Signed-off-by: Brian Haley Acked-by: David L Stevens Signed-off-by: David S. Miller --- net/ipv6/ipv6_sockglue.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 532425db11fe..1334fc174bcf 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -539,12 +539,15 @@ done: case IPV6_MULTICAST_IF: if (sk->sk_type == SOCK_STREAM) goto e_inval; - if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val) - goto e_inval; - if (__dev_get_by_index(&init_net, val) == NULL) { - retv = -ENODEV; - break; + if (val) { + if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val) + goto e_inval; + + if (__dev_get_by_index(&init_net, val) == NULL) { + retv = -ENODEV; + break; + } } np->mcast_oif = val; retv = 0; -- 2.20.1