Commit f7ff1fde authored by Nicolas Dichtel's avatar Nicolas Dichtel Committed by David S. Miller
Browse files

ip6_tunnel: remove magic mtu value 0xFFF8 

I don't know where this value comes from (probably a copy and paste and
paste and paste ...).
Let's use standard values which are a bit greater.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/davem/netdev-vger-cvs.git/commit/?id=e5afd356a411a


Signed-off-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 82612de1

net/ipv6/ip6_tunnel.c

+8 −3
Original line number Diff line number Diff line
@@ -1692,8 +1692,13 @@ int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 
		if (new_mtu < ETH_MIN_MTU)

			return -EINVAL;

	}

	if (new_mtu > 0xFFF8 - dev->hard_header_len)

	if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {

		if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)

			return -EINVAL;

	} else {

		if (new_mtu > IP_MAX_MTU - dev->hard_header_len)

			return -EINVAL;

	}

	dev->mtu = new_mtu;

	return 0;

}
@@ -1841,7 +1846,7 @@ ip6_tnl_dev_init_gen(struct net_device *dev) 
	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))

		dev->mtu -= 8;

	dev->min_mtu = ETH_MIN_MTU;

	dev->max_mtu = 0xFFF8 - dev->hard_header_len;

	dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;



	return 0;

net/ipv6/sit.c

+3 −2
Original line number Diff line number Diff line
@@ -1371,7 +1371,7 @@ static void ipip6_tunnel_setup(struct net_device *dev) 
	dev->hard_header_len	= LL_MAX_HEADER + t_hlen;

	dev->mtu		= ETH_DATA_LEN - t_hlen;

	dev->min_mtu		= IPV6_MIN_MTU;

	dev->max_mtu		= 0xFFF8 - t_hlen;

	dev->max_mtu		= IP6_MAX_MTU - t_hlen;

	dev->flags		= IFF_NOARP;

	netif_keep_dst(dev);

	dev->addr_len		= 4;
@@ -1583,7 +1583,8 @@ static int ipip6_newlink(struct net *src_net, struct net_device *dev, 
	if (tb[IFLA_MTU]) {

		u32 mtu = nla_get_u32(tb[IFLA_MTU]);



		if (mtu >= IPV6_MIN_MTU && mtu <= 0xFFF8 - dev->hard_header_len)

		if (mtu >= IPV6_MIN_MTU &&

		    mtu <= IP6_MAX_MTU - dev->hard_header_len)

			dev->mtu = mtu;

	}

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