net-next: add dev_loopback_xmit() to avoid duplicate code

Add dev_loopback_xmit() in order to deduplicate functions
ip_dev_loopback_xmit() (in net/ipv4/ip_output.c) and
ip6_dev_loopback_xmit() (in net/ipv6/ip6_output.c).

I was about to reinvent the wheel when I noticed that
ip_dev_loopback_xmit() and ip6_dev_loopback_xmit() do exactly what I
need and are not IP-only functions, but they were not available to reuse
elsewhere.

ip6_dev_loopback_xmit() does not have line "skb_dst_force(skb);", but I
understand that this is harmless, and should be in dev_loopback_xmit().

Signed-off-by: Michel Machado <michel@digirati.com.br>
CC: "David S. Miller" <davem@davemloft.net>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
CC: James Morris <jmorris@namei.org>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jpirko@redhat.com>
CC: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a0b84e3b087c..2c2ecea28a1b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1627,6 +1627,7 @@ extern int		dev_alloc_name(struct net_device *dev, const char *name);
 extern int              dev_open(struct net_device *dev);
 extern int              dev_close(struct net_device *dev);
 extern void             dev_disable_lro(struct net_device *dev);
+extern int              dev_loopback_xmit(struct sk_buff *newskb);
 extern int              dev_queue_xmit(struct sk_buff *skb);
 extern int              register_netdevice(struct net_device *dev);
 extern void             unregister_netdevice_queue(struct net_device *dev,