diff options
| author | Xin Long <lucien.xin@gmail.com> | 2017-11-11 19:06:50 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-11-13 10:44:05 +0900 |
| commit | fe1a4ca0a2b7884672661284666a0b8c183b0b1e (patch) | |
| tree | 8a775ed43e63751f6161569085c82395fcb966cc /net/ipv6 | |
| parent | 929fc0327569aa745c9c3cb68a213c22fad3f3f9 (diff) | |
ip6_gre: process toobig in a better way
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.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_gre.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 0684d0ccaaa5..b90bad7a4e56 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); } |