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Diffstat (limited to 'net/ipv6/ip6_vti.c')
-rw-r--r--net/ipv6/ip6_vti.c36
1 files changed, 23 insertions, 13 deletions
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 60b771f49fb5..6ebb2e8777f4 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -622,11 +622,12 @@ static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
return 0;
}
-static void vti6_link_config(struct ip6_tnl *t)
+static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu)
{
struct net_device *dev = t->dev;
struct __ip6_tnl_parm *p = &t->parms;
struct net_device *tdev = NULL;
+ int mtu;
memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
@@ -640,6 +641,11 @@ static void vti6_link_config(struct ip6_tnl *t)
else
dev->flags &= ~IFF_POINTOPOINT;
+ if (keep_mtu && dev->mtu) {
+ dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu);
+ return;
+ }
+
if (p->flags & IP6_TNL_F_CAP_XMIT) {
int strict = (ipv6_addr_type(&p->raddr) &
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
@@ -656,20 +662,25 @@ static void vti6_link_config(struct ip6_tnl *t)
tdev = __dev_get_by_index(t->net, p->link);
if (tdev)
- dev->mtu = max_t(int, tdev->mtu - dev->hard_header_len,
- IPV6_MIN_MTU);
+ mtu = tdev->mtu - sizeof(struct ipv6hdr);
+ else
+ mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr);
+
+ dev->mtu = max_t(int, mtu, IPV6_MIN_MTU);
}
/**
* vti6_tnl_change - update the tunnel parameters
* @t: tunnel to be changed
* @p: tunnel configuration parameters
+ * @keep_mtu: MTU was set from userspace, don't re-compute it
*
* Description:
* vti6_tnl_change() updates the tunnel parameters
**/
static int
-vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
+vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
+ bool keep_mtu)
{
t->parms.laddr = p->laddr;
t->parms.raddr = p->raddr;
@@ -679,11 +690,12 @@ vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
t->parms.proto = p->proto;
t->parms.fwmark = p->fwmark;
dst_cache_reset(&t->dst_cache);
- vti6_link_config(t);
+ vti6_link_config(t, keep_mtu);
return 0;
}
-static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
+static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p,
+ bool keep_mtu)
{
struct net *net = dev_net(t->dev);
struct vti6_net *ip6n = net_generic(net, vti6_net_id);
@@ -691,7 +703,7 @@ static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
vti6_tnl_unlink(ip6n, t);
synchronize_net();
- err = vti6_tnl_change(t, p);
+ err = vti6_tnl_change(t, p, keep_mtu);
vti6_tnl_link(ip6n, t);
netdev_state_change(t->dev);
return err;
@@ -804,7 +816,7 @@ vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
} else
t = netdev_priv(dev);
- err = vti6_update(t, &p1);
+ err = vti6_update(t, &p1, false);
}
if (t) {
err = 0;
@@ -866,10 +878,8 @@ static void vti6_dev_setup(struct net_device *dev)
dev->priv_destructor = vti6_dev_free;
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->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);
dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
netif_keep_dst(dev);
@@ -905,7 +915,7 @@ static int vti6_dev_init(struct net_device *dev)
if (err)
return err;
- vti6_link_config(t);
+ vti6_link_config(t, true);
return 0;
}
@@ -1010,7 +1020,7 @@ static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
} else
t = netdev_priv(dev);
- return vti6_update(t, &p);
+ return vti6_update(t, &p, tb && tb[IFLA_MTU]);
}
static size_t vti6_get_size(const struct net_device *dev)