4.4-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long lucien.xin@gmail.com
[ Upstream commit f3594f0a7ea36661d7fd942facd7f31a64245f1a ]
t->err_count is used to count the link failure on tunnel and an err will be reported to user socket in tx path if t->err_count is not 0. udp socket could even return EHOSTUNREACH to users.
Since commit fd58156e456d ("IPIP: Use ip-tunneling code.") removed the 'switch check' for icmp type in ipip_err(), err_count would be increased by the icmp packet with ICMP_EXC_FRAGTIME code. an link failure would be reported out due to this.
In Jianlin's case, when receiving ICMP_EXC_FRAGTIME a icmp packet, udp netperf failed with the err: send_data: data send error: No route to host (errno 113)
We expect this error reported from tunnel to socket when receiving some certain type icmp, but not ICMP_EXC_FRAGTIME, ICMP_SR_FAILED or ICMP_PARAMETERPROB ones.
This patch is to bring 'switch check' for icmp type back to ipip_err so that it only reports link failure for the right type icmp, just as in ipgre_err() and ipip6_err().
Fixes: fd58156e456d ("IPIP: Use ip-tunneling code.") Reported-by: Jianlin Shi jishi@redhat.com Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/ipip.c | 58 ++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 42 insertions(+), 16 deletions(-)
--- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -129,42 +129,68 @@ static struct rtnl_link_ops ipip_link_op static int ipip_err(struct sk_buff *skb, u32 info) {
-/* All the routers (except for Linux) return only - 8 bytes of packet payload. It means, that precise relaying of - ICMP in the real Internet is absolutely infeasible. - */ + /* All the routers (except for Linux) return only + 8 bytes of packet payload. It means, that precise relaying of + ICMP in the real Internet is absolutely infeasible. + */ struct net *net = dev_net(skb->dev); struct ip_tunnel_net *itn = net_generic(net, ipip_net_id); const struct iphdr *iph = (const struct iphdr *)skb->data; - struct ip_tunnel *t; - int err; const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; + struct ip_tunnel *t; + int err = 0; + + switch (type) { + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + /* Impossible event. */ + goto out; + default: + /* All others are translated to HOST_UNREACH. + * rfc2003 contains "deep thoughts" about NET_UNREACH, + * I believe they are just ether pollution. --ANK + */ + break; + } + break; + + case ICMP_TIME_EXCEEDED: + if (code != ICMP_EXC_TTL) + goto out; + break; + + case ICMP_REDIRECT: + break; + + default: + goto out; + }
- err = -ENOENT; t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, iph->daddr, iph->saddr, 0); - if (!t) + if (!t) { + err = -ENOENT; goto out; + }
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { - ipv4_update_pmtu(skb, dev_net(skb->dev), info, - t->parms.link, 0, IPPROTO_IPIP, 0); - err = 0; + ipv4_update_pmtu(skb, net, info, t->parms.link, 0, + iph->protocol, 0); goto out; }
if (type == ICMP_REDIRECT) { - ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, - IPPROTO_IPIP, 0); - err = 0; + ipv4_redirect(skb, net, t->parms.link, 0, iph->protocol, 0); goto out; }
- if (t->parms.iph.daddr == 0) + if (t->parms.iph.daddr == 0) { + err = -ENOENT; goto out; + }
- err = 0; if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) goto out;