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Commit 6a662719 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 



As suggested by Julian:

	Simply, flowi4_iif must not contain 0, it does not
	look logical to ignore all ip rules with specified iif.

because in fib_rule_match() we do:

        if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
                goto out;

flowi4_iif should be LOOPBACK_IFINDEX by default.

We need to move LOOPBACK_IFINDEX to include/net/flow.h:

1) It is mostly used by flowi_iif

2) Fix the following compile error if we use it in flow.h
by the patches latter:

In file included from include/linux/netfilter.h:277:0,
                 from include/net/netns/netfilter.h:5,
                 from include/net/net_namespace.h:21,
                 from include/linux/netdevice.h:43,
                 from include/linux/icmpv6.h:12,
                 from include/linux/ipv6.h:61,
                 from include/net/ipv6.h:16,
                 from include/linux/sunrpc/clnt.h:27,
                 from include/linux/nfs_fs.h:30,
                 from init/do_mounts.c:32:
include/net/flow.h: In function ‘flowi4_init_output’:
include/net/flow.h:84:32: error: ‘LOOPBACK_IFINDEX’ undeclared (first use in this function)

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarCong Wang <cwang@twopensource.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c98235cb

include/net/flow.h

+9 −1
Original line number Diff line number Diff line
@@ -11,6 +11,14 @@ 
#include <linux/in6.h>

#include <linux/atomic.h>



/*

 * ifindex generation is per-net namespace, and loopback is

 * always the 1st device in ns (see net_dev_init), thus any

 * loopback device should get ifindex 1

 */



#define LOOPBACK_IFINDEX	1



struct flowi_common {

	int	flowic_oif;

	int	flowic_iif;
@@ -80,7 +88,7 @@ static inline void flowi4_init_output(struct flowi4 *fl4, int oif, 
				      __be16 dport, __be16 sport)

{

	fl4->flowi4_oif = oif;

	fl4->flowi4_iif = 0;

	fl4->flowi4_iif = LOOPBACK_IFINDEX;

	fl4->flowi4_mark = mark;

	fl4->flowi4_tos = tos;

	fl4->flowi4_scope = scope;

include/net/net_namespace.h

+1 −8
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/list.h>

#include <linux/sysctl.h>



#include <net/flow.h>

#include <net/netns/core.h>

#include <net/netns/mib.h>

#include <net/netns/unix.h>
@@ -131,14 +132,6 @@ struct net { 
	atomic_t		fnhe_genid;

};



/*

 * ifindex generation is per-net namespace, and loopback is

 * always the 1st device in ns (see net_dev_init), thus any

 * loopback device should get ifindex 1

 */



#define LOOPBACK_IFINDEX	1



#include <linux/seq_file_net.h>



/* Init's network namespace */

net/ipv4/fib_frontend.c

+1 −1
Original line number Diff line number Diff line
@@ -250,7 +250,7 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 
	bool dev_match;



	fl4.flowi4_oif = 0;

	fl4.flowi4_iif = oif;

	fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;

	fl4.daddr = src;

	fl4.saddr = dst;

	fl4.flowi4_tos = tos;

net/ipv4/fib_semantics.c

+1 −0
Original line number Diff line number Diff line
@@ -631,6 +631,7 @@ static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, 
				.daddr = nh->nh_gw,

				.flowi4_scope = cfg->fc_scope + 1,

				.flowi4_oif = nh->nh_oif,

				.flowi4_iif = LOOPBACK_IFINDEX,

			};



			/* It is not necessary, but requires a bit of thinking */

net/ipv4/ipmr.c

+1 −1
Original line number Diff line number Diff line
@@ -455,7 +455,7 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev) 
	struct mr_table *mrt;

	struct flowi4 fl4 = {

		.flowi4_oif	= dev->ifindex,

		.flowi4_iif	= skb->skb_iif,

		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,

		.flowi4_mark	= skb->mark,

	};

	int err;