gre: Move MTU setting out of ipgre_tunnel_bind_dev
This patch moves the dev->mtu setting out of ipgre_tunnel_bind_dev.
This is in prepartion of using rtnl_link where we'll need to make
the MTU setting conditional on whether the user has supplied an
MTU. This also requires the move of the ipgre_tunnel_bind_dev
call out of the dev->init function so that we can access the user
parameters later.
This patch also adds a check to prevent setting the MTU below
the minimum of 68.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index fd192d6..80622dd 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -119,6 +119,7 @@
static int ipgre_tunnel_init(struct net_device *dev);
static void ipgre_tunnel_setup(struct net_device *dev);
+static int ipgre_tunnel_bind_dev(struct net_device *dev);
/* Fallback tunnel: no source, no destination, no key, no options */
@@ -289,6 +290,8 @@
nt = netdev_priv(dev);
nt->parms = *parms;
+ dev->mtu = ipgre_tunnel_bind_dev(dev);
+
if (register_netdevice(dev) < 0)
goto failed_free;
@@ -773,7 +776,7 @@
return 0;
}
-static void ipgre_tunnel_bind_dev(struct net_device *dev)
+static int ipgre_tunnel_bind_dev(struct net_device *dev)
{
struct net_device *tdev = NULL;
struct ip_tunnel *tunnel;
@@ -821,9 +824,14 @@
addend += 4;
}
dev->needed_headroom = addend + hlen;
- dev->mtu = mtu - dev->hard_header_len - addend;
+ mtu -= dev->hard_header_len - addend;
+
+ if (mtu < 68)
+ mtu = 68;
+
tunnel->hlen = addend;
+ return mtu;
}
static int
@@ -917,7 +925,7 @@
t->parms.iph.frag_off = p.iph.frag_off;
if (t->parms.link != p.link) {
t->parms.link = p.link;
- ipgre_tunnel_bind_dev(dev);
+ dev->mtu = ipgre_tunnel_bind_dev(dev);
netdev_state_change(dev);
}
}
@@ -1108,8 +1116,6 @@
memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
- ipgre_tunnel_bind_dev(dev);
-
if (iph->daddr) {
#ifdef CONFIG_NET_IPGRE_BROADCAST
if (ipv4_is_multicast(iph->daddr)) {