Commit 5a455275 authored Apr 11, 2014 by Nicolas Dichtel Committed by David S. Miller Apr 12, 2014

gre: don't allow to add the same tunnel twice



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 c5441932 ("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>

parent 810d8ced

net/ipv4/ip_gre.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

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