[PATCH 3.13 010/212] gre: don't allow to add the same tunnel twice

Kamal Mostafa
2014-06-17T21:41:44Z

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

[ Upstream commit 5a4552752d8f7f4cef1d98775ece7adb7616fde2 ]

Before the patch, it was possible to add two times the same tunnel:
ip l a gre1 type gre remote 10.16.0.121 local 10.16.0.249
ip l a gre2 type gre remote 10.16.0.121 local 10.16.0.249

It was possible, because ip_tunnel_newlink() calls ip_tunnel_find() with the
argument dev->type, which was set only later (when calling ndo_init handler
in register_netdevice()). Let's set this type in the setup handler, which is
called before newlink handler.

Introduced by commit c54419321455 ("GRE: Refactor GRE tunneling code.").

CC: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
net/ipv4/ip_gre.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index d306360..b3becd0 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -463,6 +463,7 @@ static const struct net_device_ops ipgre_netdev_ops = {
static void ipgre_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &ipgre_netdev_ops;
+ dev->type = ARPHRD_IPGRE;
ip_tunnel_setup(dev, ipgre_net_id);
}

@@ -501,7 +502,6 @@ static int ipgre_tunnel_init(struct net_device *dev)
memcpy(dev->dev_addr, &iph->saddr, 4);
memcpy(dev->broadcast, &iph->daddr, 4);

- dev->type = ARPHRD_IPGRE;
dev->flags = IFF_NOARP;
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
dev->addr_len = 4;
--
1.9.1