Now ip6gre processes toobig icmp packet by setting gre dev's mtu in
ip6gre_err, which would cause few things not good:
- It couldn't set mtu with dev_set_mtu due to it's not in user context,
which causes route cache and idev->cnf.mtu6 not to be updated.
- It has to update sk dst pmtu in tx path according to gredev->mtu for
ip6gre, while it updates pmtu again according to lower dst pmtu in
ip6_tnl_xmit.
- To change dev->mtu by toobig icmp packet is not a good idea, it should
only work on pmtu.
This patch is to process toobig by updating the lower dst's pmtu, as later
sk dst pmtu will be updated in ip6_tnl_xmit, the same way as in ip4gre.
Note that gre dev's mtu will not be updated any more, it doesn't make any
sense to change dev's mtu after receiving a toobig packet.
Signed-off-by: Xin Long <lucien....@gmail.com>
---
net/ipv6/ip6_gre.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 0684d0c..b90bad7 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -403,9 +403,8 @@ static void ip6gre_err(struct sk_buff *skb, struct
inet6_skb_parm *opt,
return;
switch (type) {
- __u32 teli;
struct ipv6_tlv_tnl_enc_lim *tel;
- __u32 mtu;
+ __u32 teli;
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or
inactive!\n",
t->parms.name);
@@ -436,12 +435,7 @@ static void ip6gre_err(struct sk_buff *skb, struct
inet6_skb_parm *opt,
}
return;
case ICMPV6_PKT_TOOBIG:
- mtu = be32_to_cpu(info) - offset - t->tun_hlen;
- if (t->dev->type == ARPHRD_ETHER)
- mtu -= ETH_HLEN;
- if (mtu < IPV6_MIN_MTU)
- mtu = IPV6_MIN_MTU;
- t->dev->mtu = mtu;
+ ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
return;
case NDISC_REDIRECT:
ip6_redirect(skb, net, skb->dev->ifindex, 0,
@@ -508,7 +502,6 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
__u32 *pmtu, __be16 proto)
{
struct ip6_tnl *tunnel = netdev_priv(dev);
- struct dst_entry *dst = skb_dst(skb);
__be16 protocol;
if (dev->type == ARPHRD_ETHER)
@@ -527,10 +520,6 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
- /* TooBig packet may have updated dst->dev's mtu */
- if (dst && dst_mtu(dst) > dst->dev->mtu)
- dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
-
return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
NEXTHDR_GRE);
}
--
2.1.0
