From b96f9afee4eb5229c80afa3d97ccf725fb1b89a6 Mon Sep 17 00:00:00 2001 From: Jarod Wilson Date: Thu, 20 Oct 2016 13:55:24 -0400 Subject: [PATCH] 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" CC: Alexey Kuznetsov CC: James Morris CC: Hideaki YOSHIFUJI CC: Patrick McHardy Signed-off-by: Jarod Wilson Signed-off-by: David S. Miller --- net/ipv4/ip_tunnel.c | 6 +++++- net/ipv6/ip6_tunnel.c | 4 +++- net/ipv6/ip6_vti.c | 21 ++------------------- net/ipv6/sit.c | 14 ++------------ 4 files changed, 12 insertions(+), 33 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 5719d6ba0824..12a92e3349ed 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -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) { diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 6a66adba0c22..3a70567846aa 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -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; diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index 8a02ca8a11af..35c5b2d8c401 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -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); diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index b1cdf8009d29..dc7a3449ffc1 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -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; -- 2.39.5