linux/net/ipv6
Xin Long c9fefa0819 ip6_tunnel: get the min mtu properly in ip6_tnl_xmit
Now it's using IPV6_MIN_MTU as the min mtu in ip6_tnl_xmit, but
IPV6_MIN_MTU actually only works when the inner packet is ipv6.

With IPV6_MIN_MTU for ipv4 packets, the new pmtu for inner dst
couldn't be set less than 1280. It would cause tx_err and the
packet to be dropped when the outer dst pmtu is close to 1280.

Jianlin found it by running ipv4 traffic with the topo:

  (client) gre6 <---> eth1 (route) eth2 <---> gre6 (server)

After changing eth2 mtu to 1300, the performance became very
low, or the connection was even broken. The issue also affects
ip4ip6 and ip6ip6 tunnels.

So if the inner packet is ipv4, 576 should be considered as the
min mtu.

Note that for ip4ip6 and ip6ip6 tunnels, the inner packet can
only be ipv4 or ipv6, but for gre6 tunnel, it may also be ARP.
This patch using 576 as the min mtu for non-ipv6 packet works
for all those cases.

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>
2017-12-19 13:45:33 -05:00
..
ila ila: Add a hook type for LWT routes 2017-11-08 11:20:49 +09:00
netfilter netfilter: ip6t_MASQUERADE: add dependency on conntrack module 2017-12-11 17:04:50 +01:00
addrconf_core.c net: ipv6: Make inet6addr_validator a blocking notifier 2017-10-20 13:15:07 +01:00
addrconf.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
addrlabel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
af_inet6.c ipv6: Implement limits on Hop-by-Hop and Destination options 2017-11-03 09:50:22 +09:00
ah6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
anycast.c net, ipv6: convert ifacaddr6.aca_refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
calipso.c net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
datagram.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
esp6_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-09-01 17:42:05 -07:00
esp6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
exthdrs_core.c net: ipv6: remove unused code in ipv6_find_hdr() 2017-10-05 21:53:02 -07:00
exthdrs_offload.c
exthdrs.c ipv6: Implement limits on Hop-by-Hop and Destination options 2017-11-03 09:50:22 +09:00
fib6_notifier.c net: Add module reference to FIB notifiers 2017-09-01 20:33:42 -07:00
fib6_rules.c net: ipv6: avoid overhead when no custom FIB rules are installed 2017-08-08 21:40:08 -07:00
fou6.c fou: make local function static 2017-05-21 13:42:36 -04:00
icmp.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
inet6_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
inet6_hashtables.c net: ipv6: add second dif to inet6 socket lookups 2017-08-07 11:39:22 -07:00
ip6_checksum.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_fib.c treewide: setup_timer() -> timer_setup() (2 field) 2017-11-21 15:57:09 -08:00
ip6_flowlabel.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
ip6_gre.c ip6_gre: remove the incorrect mtu limit for ipgre tap 2017-12-19 13:45:32 -05:00
ip6_icmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-20 10:35:33 -04:00
ip6_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
ip6_offload.h udp: Add GRO functions to UDP socket 2016-04-07 16:53:29 -04:00
ip6_output.c ipv6: flowlabel: do not leave opt->tot_len with garbage 2017-10-22 03:22:24 +01:00
ip6_tunnel.c ip6_tunnel: get the min mtu properly in ip6_tnl_xmit 2017-12-19 13:45:33 -05:00
ip6_udp_tunnel.c ip6_udp_tunnel: remove unused IPCB related codes 2016-11-02 15:18:36 -04:00
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-05 18:19:22 -07:00
ip6mr.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
ipcomp6.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
ipv6_sockglue.c net-ipv6: add support for sockopt(SOL_IPV6, IPV6_FREEBIND) 2017-09-30 05:30:52 +01:00
Kconfig ipv6: sr: add helper functions for seg6local 2017-08-25 17:10:24 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mcast_snoop.c
mcast.c ipv6: mcast: better catch silly mtu values 2017-12-13 13:13:15 -05:00
mip6.c ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ndisc.c net: ipv6: sysctl to specify IPv6 ND traffic class 2017-11-11 15:13:02 +09:00
netfilter.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
output_core.c net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
ping.c net/ipv6: Convert icmpv6_push_pending_frames to void 2017-10-06 09:52:31 -07:00
proc.c proc: snmp6: Use correct type in memset 2017-06-12 09:53:14 -04:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
reassembly.c inet: frags: Convert timers to use timer_setup() 2017-10-18 12:39:55 +01:00
route.c ipv6: icmp6: Allow icmp messages to be looped back 2017-12-16 22:51:26 -05:00
seg6_hmac.c ipv6: sr: Use ARRAY_SIZE macro 2017-09-01 18:35:23 -07:00
seg6_iptunnel.c ipv6: sr: add support for encapsulation of L2 frames 2017-08-25 17:10:23 -07:00
seg6_local.c ipv6: sr: remove duplicate routing header type check 2017-09-11 14:34:10 -07:00
seg6.c ipv6: sr: define core operations for seg6local lightweight tunnel 2017-08-07 14:16:22 -07:00
sit.c sit: update frag_off info 2017-11-30 10:25:41 -05:00
syncookies.c tcp: Namespace-ify sysctl_tcp_workaround_signed_windows 2017-10-28 19:24:38 +09:00
sysctl_net_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
tcp_ipv6.c tcp md5sig: Use skb's saddr when replying to an incoming segment 2017-12-12 11:15:42 -05:00
tcpv6_offload.c
tunnel6.c
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
udp.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
udplite.c udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
xfrm6_input.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm6_mode_ro.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_transport.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_tunnel.c xfrm: Add encapsulation header offsets while SKB is not encrypted 2017-04-14 10:07:39 +02:00
xfrm6_output.c xfrm: Add an IPsec hardware offloading API 2017-04-14 10:06:10 +02:00
xfrm6_policy.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
xfrm6_protocol.c xfrm: input: constify xfrm_input_afinfo 2017-02-09 10:22:17 +01:00
xfrm6_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_tunnel.c xfrm6_tunnel: exit_net cleanup check added 2017-11-14 15:46:17 +09:00