From f8d20b46ce55cf40afb30dcef6d9288f7ef46d9b Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 26 Oct 2017 19:23:27 +0800 Subject: ip6_gre: only increase err_count for some certain type icmpv6 in ip6gre_err The similar fix in patch 'ipip: only increase err_count for some certain type icmp in ipip_err' is needed for ip6gre_err. In Jianlin's case, udp netperf broke even when receiving a TooBig icmpv6 packet. Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: Jianlin Shi Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/ipv6/ip6_gre.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 1602b491b281..fb595e8dc15b 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -408,13 +408,16 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, case ICMPV6_DEST_UNREACH: net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n", t->parms.name); - break; + if (code != ICMPV6_PORT_UNREACH) + break; + return; case ICMPV6_TIME_EXCEED: if (code == ICMPV6_EXC_HOPLIMIT) { net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", t->parms.name); + break; } - break; + return; case ICMPV6_PARAMPROB: teli = 0; if (code == ICMPV6_HDR_FIELD) @@ -430,7 +433,7 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n", t->parms.name); } - break; + return; case ICMPV6_PKT_TOOBIG: mtu = be32_to_cpu(info) - offset - t->tun_hlen; if (t->dev->type == ARPHRD_ETHER) @@ -438,7 +441,7 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; t->dev->mtu = mtu; - break; + return; } if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO)) -- cgit v1.2.3 From 8aec4959d832bae0889a8e2f348973b5e4abffef Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 26 Oct 2017 19:27:17 +0800 Subject: ip6_gre: update dst pmtu if dev mtu has been updated by toobig in __gre6_xmit When receiving a Toobig icmpv6 packet, ip6gre_err would just set tunnel dev's mtu, that's not enough. For skb_dst(skb)'s pmtu may still be using the old value, it has no chance to be updated with tunnel dev's mtu. Jianlin found this issue by reducing route's mtu while running netperf, the performance went to 0. ip6ip6 and ip4ip6 tunnel can work well with this, as they lookup the upper dst and update_pmtu it's pmtu or icmpv6_send a Toobig to upper socket after setting tunnel dev's mtu. We couldn't do that for ip6_gre, as gre's inner packet could be any protocol, it's difficult to handle them (like lookup upper dst) in a good way. So this patch is to fix it by updating skb_dst(skb)'s pmtu when dev->mtu < skb_dst(skb)'s pmtu in tx path. It's safe to do this update there, as usually dev->mtu <= skb_dst(skb)'s pmtu and no performance regression can be caused by this. Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: Jianlin Shi Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/ipv6/ip6_gre.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index fb595e8dc15b..59c121b932ac 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -503,8 +503,8 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb, __u32 *pmtu, __be16 proto) { struct ip6_tnl *tunnel = netdev_priv(dev); - __be16 protocol = (dev->type == ARPHRD_ETHER) ? - htons(ETH_P_TEB) : proto; + struct dst_entry *dst = skb_dst(skb); + __be16 protocol; if (dev->type == ARPHRD_ETHER) IPCB(skb)->flags = 0; @@ -518,9 +518,14 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb, tunnel->o_seqno++; /* Push GRE header. */ + protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto; 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); } -- cgit v1.2.3