Commit b96f9afe authored by Jarod Wilson's avatar Jarod Wilson Committed by David S. Miller
Browse files

ipv4/6: use core net MTU range checking 



ipv4/ip_tunnel:
- min_mtu = 68, max_mtu = 0xFFF8 - dev->hard_header_len - t_hlen
- preserve all ndo_change_mtu checks for now to prevent regressions

ipv6/ip6_tunnel:
- min_mtu = 68, max_mtu = 0xFFF8 - dev->hard_header_len
- preserve all ndo_change_mtu checks for now to prevent regressions

ipv6/ip6_vti:
- min_mtu = 1280, max_mtu = 65535
- remove redundant vti6_change_mtu

ipv6/sit:
- min_mtu = 1280, max_mtu = 0xFFF8 - t_hlen
- remove redundant ipip6_tunnel_change_mtu

CC: netdev@vger.kernel.org
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>
Signed-off-by: default avatarJarod Wilson <jarod@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 46b3ef4c

net/ipv4/ip_tunnel.c

+5 −1
Original line number Diff line number Diff line
@@ -358,6 +358,7 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, 
{

	struct ip_tunnel *nt;

	struct net_device *dev;

	int t_hlen;



	BUG_ON(!itn->fb_tunnel_dev);

	dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops, parms);
@@ -367,6 +368,9 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, 
	dev->mtu = ip_tunnel_bind_dev(dev);



	nt = netdev_priv(dev);

	t_hlen = nt->hlen + sizeof(struct iphdr);

	dev->min_mtu = ETH_MIN_MTU;

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

	ip_tunnel_add(itn, nt);

	return nt;

}
@@ -929,7 +933,7 @@ int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 
	int t_hlen = tunnel->hlen + sizeof(struct iphdr);

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



	if (new_mtu < 68)

	if (new_mtu < ETH_MIN_MTU)

		return -EINVAL;



	if (new_mtu > max_mtu) {

net/ipv6/ip6_tunnel.c

+3 −1
Original line number Diff line number Diff line
@@ -1634,7 +1634,7 @@ int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 
	struct ip6_tnl *tnl = netdev_priv(dev);



	if (tnl->parms.proto == IPPROTO_IPIP) {

		if (new_mtu < 68)

		if (new_mtu < ETH_MIN_MTU)

			return -EINVAL;

	} else {

		if (new_mtu < IPV6_MIN_MTU)
@@ -1787,6 +1787,8 @@ ip6_tnl_dev_init_gen(struct net_device *dev) 
	dev->mtu = ETH_DATA_LEN - t_hlen;

	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;



	return 0;

net/ipv6/ip6_vti.c

+2 −19
Original line number Diff line number Diff line
@@ -812,30 +812,11 @@ vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 
	return err;

}



/**

 * vti6_tnl_change_mtu - change mtu manually for tunnel device

 *   @dev: virtual device associated with tunnel

 *   @new_mtu: the new mtu

 *

 * Return:

 *   0 on success,

 *   %-EINVAL if mtu too small

 **/

static int vti6_change_mtu(struct net_device *dev, int new_mtu)

{

	if (new_mtu < IPV6_MIN_MTU)

		return -EINVAL;



	dev->mtu = new_mtu;

	return 0;

}



static const struct net_device_ops vti6_netdev_ops = {

	.ndo_init	= vti6_dev_init,

	.ndo_uninit	= vti6_dev_uninit,

	.ndo_start_xmit = vti6_tnl_xmit,

	.ndo_do_ioctl	= vti6_ioctl,

	.ndo_change_mtu = vti6_change_mtu,

	.ndo_get_stats64 = ip_tunnel_get_stats64,

	.ndo_get_iflink = ip6_tnl_get_iflink,

};
@@ -855,6 +836,8 @@ static void vti6_dev_setup(struct net_device *dev) 
	dev->type = ARPHRD_TUNNEL6;

	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);

	dev->mtu = ETH_DATA_LEN;

	dev->min_mtu = IPV6_MIN_MTU;

	dev->max_mtu = IP_MAX_MTU;

	dev->flags |= IFF_NOARP;

	dev->addr_len = sizeof(struct in6_addr);

	netif_keep_dst(dev);

net/ipv6/sit.c

+2 −12
Original line number Diff line number Diff line
@@ -1318,23 +1318,11 @@ done: 
	return err;

}



static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	int t_hlen = tunnel->hlen + sizeof(struct iphdr);



	if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - t_hlen)

		return -EINVAL;

	dev->mtu = new_mtu;

	return 0;

}



static const struct net_device_ops ipip6_netdev_ops = {

	.ndo_init	= ipip6_tunnel_init,

	.ndo_uninit	= ipip6_tunnel_uninit,

	.ndo_start_xmit	= sit_tunnel_xmit,

	.ndo_do_ioctl	= ipip6_tunnel_ioctl,

	.ndo_change_mtu	= ipip6_tunnel_change_mtu,

	.ndo_get_stats64 = ip_tunnel_get_stats64,

	.ndo_get_iflink = ip_tunnel_get_iflink,

};
@@ -1365,6 +1353,8 @@ static void ipip6_tunnel_setup(struct net_device *dev) 
	dev->type		= ARPHRD_SIT;

	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->flags		= IFF_NOARP;

	netif_keep_dst(dev);

	dev->addr_len		= 4;

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