[PATCH 14/16] ipv4: Kill rt->rt_oif

Never actually used.

It was being set on output routes to the original OIF specified in the
flow key used for the lookup.

But the only user was in ipmr_rt_fib_lookup() which always runs on an
input route.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/route.h     |    1 -
 net/ipv4/ipmr.c         |    1 -
 net/ipv4/route.c        |    5 -----
 net/ipv4/xfrm4_policy.c |    1 -
 4 files changed, 8 deletions(-)

diff --git a/include/net/route.h b/include/net/route.h
index 3c1eeab..e789a92 100644
--- a/include/net/route.h
+++ b/include/net/route.h

@@ -50,7 +50,6 @@ struct rtable {
 
 	int			rt_route_iif;
 	int			rt_iif;
-	int			rt_oif;
 
 	/* Info on neighbour */
 	__be32			rt_gateway;

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index eee3bf6..fa75f73 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c

@@ -1795,7 +1795,6 @@ static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
 		.daddr = iph->daddr,
 		.saddr = iph->saddr,
 		.flowi4_tos = RT_TOS(iph->tos),
-		.flowi4_oif = rt->rt_oif,
 		.flowi4_iif = rt->rt_iif,
 		.flowi4_mark = skb->mark,
 	};

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1d4e317..b7e99a6 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c

@@ -1326,7 +1326,6 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	rth->rt_type	= RTN_MULTICAST;
 	rth->rt_route_iif = dev->ifindex;
 	rth->rt_iif	= dev->ifindex;
-	rth->rt_oif	= 0;
 	rth->rt_pmtu	= 0;
 	rth->rt_gateway	= 0;
 	rth->fi = NULL;

@@ -1457,7 +1456,6 @@ static int __mkroute_input(struct sk_buff *skb,
 	rth->rt_type = res->type;
 	rth->rt_route_iif = in_dev->dev->ifindex;
 	rth->rt_iif 	= in_dev->dev->ifindex;
-	rth->rt_oif 	= 0;
 	rth->rt_pmtu	= 0;
 	rth->rt_gateway	= 0;
 	rth->fi = NULL;

@@ -1636,7 +1634,6 @@ local_input:
 	rth->rt_type	= res.type;
 	rth->rt_route_iif = dev->ifindex;
 	rth->rt_iif	= dev->ifindex;
-	rth->rt_oif	= 0;
 	rth->rt_pmtu	= 0;
 	rth->rt_gateway	= 0;
 	rth->fi = NULL;

@@ -1802,7 +1799,6 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 	rth->rt_type	= type;
 	rth->rt_route_iif = 0;
 	rth->rt_iif	= orig_oif ? : dev_out->ifindex;
-	rth->rt_oif	= orig_oif;
 	rth->rt_pmtu	= 0;
 	rth->rt_gateway = 0;
 	rth->fi = NULL;

@@ -2079,7 +2075,6 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
 
 		rt->rt_route_iif = ort->rt_route_iif;
 		rt->rt_iif = ort->rt_iif;
-		rt->rt_oif = ort->rt_oif;
 		rt->rt_pmtu = ort->rt_pmtu;
 
 		rt->rt_genid = rt_genid(net);

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 6074b69..3c99b4c 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c

@@ -81,7 +81,6 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 
 	xdst->u.rt.rt_route_iif = fl4->flowi4_iif;
 	xdst->u.rt.rt_iif = fl4->flowi4_iif;
-	xdst->u.rt.rt_oif = fl4->flowi4_oif;
 
 	xdst->u.dst.dev = dev;
 	dev_hold(dev);

-- 
1.7.10.4

	Hello,

	Added CC to Patrick McHardy as mrule author...

On Thu, 19 Jul 2012, David Miller wrote:

Never actually used.

It was being set on output routes to the original OIF specified in the
flow key used for the lookup.

But the only user was in ipmr_rt_fib_lookup() which always runs on an
input route.

	It can also work with output route, it seems
copy of locally originated traffic can be sent to local
mrouter for forwarding to remote recipients. Now we search
this mrouter with rules. We can loopback traffic to
local applications or to local multicast router (even
when no local applications are listening).

	But it was wrong at first place to use rt_iif
here. May be we should provide devices to "mrule" just
like we do for "rule", with the only difference that
oif now is possible to match outdev instead of preferred
device, i.e. oif is always set for output routes.

	.flowi4_oif = rt_is_output_route(rt) ?
			skb->dev->ifindex : 0,
	.flowi4_iif = rt_is_output_route(rt) ?
			net->loopback_dev->ifindex :
			skb->dev->ifindex;

	Before now it was risky to use just "mrule iif XXX"
because rt_iif contains the output device for output
routes and we can match output route by mistake.

	With above code it is now safe to use just
"iif eth0" for input routes and "iif lo" for output
routes. Here is what will see the mrule now:

local_app -> mrouter: lo->dev
remote_app -> mrouter: dev->0 (only iif match is possible)

	Let me know if patch is needed

Regards

--
Julian Anastasov [off-list ref]

From: Julian Anastasov <ja@ssi.bg>
Date: Fri, 20 Jul 2012 04:10:12 +0300 (EEST)

quoted

@@ -1795,7 +1795,6 @@ static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
 		.daddr = iph->daddr,
 		.saddr = iph->saddr,
 		.flowi4_tos = RT_TOS(iph->tos),
-		.flowi4_oif = rt->rt_oif,
 		.flowi4_iif = rt->rt_iif,
 		.flowi4_mark = skb->mark,

	But it was wrong at first place to use rt_iif
here. May be we should provide devices to "mrule" just
like we do for "rule", with the only difference that
oif now is possible to match outdev instead of preferred
device, i.e. oif is always set for output routes.

	.flowi4_oif = rt_is_output_route(rt) ?
			skb->dev->ifindex : 0,
	.flowi4_iif = rt_is_output_route(rt) ?
			net->loopback_dev->ifindex :
			skb->dev->ifindex;

Ok.

	Let me know if patch is needed

I'll take care of it myself today, thanks.