From d46a9d678e4c9fac1e968d0593e4dba683389324 Mon Sep 17 00:00:00 2001
From: David Ahern <dsa@cumulusnetworks.com>
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 <thehajime@gmail.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
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 be5d2879b5d81..946880ad48acd 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);
--
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