| Message ID | 1397186427.16584.86.camel@edumazet-glaptop2.roam.corp.google.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > Francois reported that setting big mtu on loopback device could prevent > tcp sessions making progress. > > We do not support (yet ?) IPv6 Jumbograms and cook corrupted packets. > > We must limit the IPv6 MTU to (65535 + 40) bytes in theory. > > Tested: > > ifconfig lo mtu 70000 > netperf -H ::1 > > Before patch : Throughput : 0.05 Mbits > > After patch : Throughput : 35484 Mbits > > Reported-by: Francois WELLENREITER <f.wellenreiter@gmail.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> --yoshfuji -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Eric, YOSHIFUJI Hideaki wrote: > Eric Dumazet wrote: >> From: Eric Dumazet <edumazet@google.com> >> >> Francois reported that setting big mtu on loopback device could prevent >> tcp sessions making progress. >> >> We do not support (yet ?) IPv6 Jumbograms and cook corrupted packets. >> >> We must limit the IPv6 MTU to (65535 + 40) bytes in theory. >> >> Tested: >> >> ifconfig lo mtu 70000 >> netperf -H ::1 >> >> Before patch : Throughput : 0.05 Mbits >> >> After patch : Throughput : 35484 Mbits >> >> Reported-by: Francois WELLENREITER <f.wellenreiter@gmail.com> >> Signed-off-by: Eric Dumazet <edumazet@google.com> > Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Oops, you need to change the subject as well. Otherwise, I am okay. Thanks a lot. --yoshfuji -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Thu, 10 Apr 2014 20:20:27 -0700 > +/* We do not (yet ?) support IPv6 jumbograms (RFC 2675) > + * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header > + */ > +#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) Hmmm, does this still match $Subj? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2014-04-10 at 23:30 -0400, David Miller wrote: > From: Eric Dumazet <eric.dumazet@gmail.com> > Date: Thu, 10 Apr 2014 20:20:27 -0700 > > > +/* We do not (yet ?) support IPv6 jumbograms (RFC 2675) > > + * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header > > + */ > > +#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) > > Hmmm, does this still match $Subj? Ugh, sorry, I had to run. I'll resend. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 3c3bb184eb8f..6c4f5eac98e7 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -32,6 +32,11 @@ struct route_info { #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010 #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020 +/* We do not (yet ?) support IPv6 jumbograms (RFC 2675) + * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header + */ +#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr)) + /* * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate * between IPV6_ADDR_PREFERENCES socket option values diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 5015c50a5ba7..5ea462eacd9f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1338,7 +1338,7 @@ static unsigned int ip6_mtu(const struct dst_entry *dst) unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); if (mtu) - return mtu; + goto out; mtu = IPV6_MIN_MTU; @@ -1348,7 +1348,8 @@ static unsigned int ip6_mtu(const struct dst_entry *dst) mtu = idev->cnf.mtu6; rcu_read_unlock(); - return mtu; +out: + return min_t(unsigned int, mtu, IP6_MAX_MTU); } static struct dst_entry *icmp6_dst_gc_list;