From d46a9d678e4c9fac1e968d0593e4dba683389324 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 21 Oct 2015 08:42:22 -0700 Subject: [PATCH] net: ipv6: Dont add RT6_LOOKUP_F_IFACE flag if saddr set 741a11d9e410 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set") adds the RT6_LOOKUP_F_IFACE flag to make device index mismatch fatal if oif is given. Hajime reported that this change breaks the Mobile IPv6 use case that wants to force the message through one interface yet use the source address from another interface. Handle this case by only adding the flag if oif is set and saddr is not set. Fixes: 741a11d9e410 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set") Cc: Hajime Tazaki Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index be5d2879b5d8..946880ad48ac 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1193,14 +1193,16 @@ struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk, struct flowi6 *fl6) { int flags = 0; + bool any_src; fl6->flowi6_iif = LOOPBACK_IFINDEX; + any_src = ipv6_addr_any(&fl6->saddr); if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) || - fl6->flowi6_oif) + (fl6->flowi6_oif && any_src)) flags |= RT6_LOOKUP_F_IFACE; - if (!ipv6_addr_any(&fl6->saddr)) + if (!any_src) flags |= RT6_LOOKUP_F_HAS_SADDR; else if (sk) flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);