linux-toradex.git/include/net/ip_tunnels.h, branch v4.4.93

tunnels: Remove encapsulation offloads on decap.

2016-10-31T10:13:59+00:00

commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168 upstream.

If a packet is either locally encapsulated or processed through GRO
it is marked with the offloads that it requires. However, when it is
decapsulated these tunnel offload indications are not removed. This
means that if we receive an encapsulated TCP packet, aggregate it with
GRO, decapsulate, and retransmit the resulting frame on a NIC that does
not support encapsulation, we won't be able to take advantage of hardware
offloads even though it is just a simple TCP packet at this point.

This fixes the problem by stripping off encapsulation offload indications
when packets are decapsulated.

The performance impacts of this bug are significant. In a test where a
Geneve encapsulated TCP stream is sent to a hypervisor, GRO'ed, decapsulated,
and bridged to a VM performance is improved by 60% (5Gbps->8Gbps) as a
result of avoiding unnecessary segmentation at the VM tap interface.

Reported-by: Ramu Ramamurthy 
Fixes: 68c33163 ("v4 GRE: Add TCP segmentation offload for GRE")
Signed-off-by: Jesse Gross 
Signed-off-by: David S. Miller 
(backported from commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168)
[adapt iptunnel_pull_header arguments, avoid 7f290c9]
Signed-off-by: Stefan Bader 
Signed-off-by: Juerg Haefliger 
Signed-off-by: Greg Kroah-Hartman

vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices

2016-06-24T17:18:18+00:00

[ Upstream commit 7e059158d57b79159eaf1f504825d19866ef2c42 ]

Prior to 4.3, openvswitch tunnel vports (vxlan, gre and geneve) could
transmit vxlan packets of any size, constrained only by the ability to
send out the resulting packets.  4.3 introduced netdevs corresponding
to tunnel vports.  These netdevs have an MTU, which limits the size of
a packet that can be successfully encapsulated.  The default MTU
values are low (1500 or less), which is awkwardly small in the context
of physical networks supporting jumbo frames, and leads to a
conspicuous change in behaviour for userspace.

Instead, set the MTU on openvswitch-created netdevs to be the relevant
maximum (i.e. the maximum IP packet size minus any relevant overhead),
effectively restoring the behaviour prior to 4.3.

Signed-off-by: David Wragg 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ip_tunnel: disable preemption when updating per-cpu tstats

2015-11-16T19:14:32+00:00

Drivers like vxlan use the recently introduced
udp_tunnel_xmit_skb/udp_tunnel6_xmit_skb APIs. udp_tunnel6_xmit_skb
makes use of ip6tunnel_xmit, and ip6tunnel_xmit, after sending the
packet, updates the struct stats using the usual
u64_stats_update_begin/end calls on this_cpu_ptr(dev->tstats).
udp_tunnel_xmit_skb makes use of iptunnel_xmit, which doesn't touch
tstats, so drivers like vxlan, immediately after, call
iptunnel_xmit_stats, which does the same thing - calls
u64_stats_update_begin/end on this_cpu_ptr(dev->tstats).

While vxlan is probably fine (I don't know?), calling a similar function
from, say, an unbound workqueue, on a fully preemptable kernel causes
real issues:

[  188.434537] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u8:0/6
[  188.435579] caller is debug_smp_processor_id+0x17/0x20
[  188.435583] CPU: 0 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.6 #2
[  188.435607] Call Trace:
[  188.435611]  [] dump_stack+0x4f/0x7b
[  188.435615]  [] check_preemption_disabled+0x19d/0x1c0
[  188.435619]  [] debug_smp_processor_id+0x17/0x20

The solution would be to protect the whole
this_cpu_ptr(dev->tstats)/u64_stats_update_begin/end blocks with
disabling preemption and then reenabling it.

Signed-off-by: Jason A. Donenfeld 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv4: send arp replies to the correct tunnel

2015-09-24T21:31:36+00:00

When using ip lwtunnels, the additional data for xmit (basically, the actual
tunnel to use) are carried in ip_tunnel_info either in dst->lwtstate or in
metadata dst. When replying to ARP requests, we need to send the reply to
the same tunnel the request came from. This means we need to construct
proper metadata dst for ARP replies.

We could perform another route lookup to get a dst entry with the correct
lwtstate. However, this won't always ensure that the outgoing tunnel is the
same as the incoming one, and it won't work anyway for IPv4 duplicate
address detection.

The only thing to do is to "reverse" the ip_tunnel_info.

Signed-off-by: Jiri Benc 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller

ip-tunnel: Use API to access tunnel metadata options.

2015-08-31T19:28:56+00:00

Currently tun-info options pointer is used in few cases to
pass options around. But tunnel options can be accessed using
ip_tunnel_info_opts() API without using the pointer. Following
patch removes the redundant pointer and consistently make use
of API.

Signed-off-by: Pravin B Shelar 
Acked-by: Thomas Graf 
Reviewed-by: Jesse Gross 
Signed-off-by: David S. Miller

ip_tunnels: record IP version in tunnel info

2015-08-29T20:07:54+00:00

There's currently nothing preventing directing packets with IPv6
encapsulation data to IPv4 tunnels (and vice versa). If this happens,
IPv6 addresses are incorrectly interpreted as IPv4 ones.

Track whether the given ip_tunnel_key contains IPv4 or IPv6 data. Store this
in ip_tunnel_info. Reject packets at appropriate places if they are supposed
to be encapsulated into an incompatible protocol.

Signed-off-by: Jiri Benc 
Acked-by: Alexei Starovoitov 
Acked-by: Thomas Graf 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller

ip_tunnels: convert the mode field of ip_tunnel_info to flags

2015-08-29T20:07:54+00:00

The mode field holds a single bit of information only (whether the
ip_tunnel_info struct is for rx or tx). Change the mode field to bit flags.
This allows more mode flags to be added.

Signed-off-by: Jiri Benc 
Acked-by: Alexei Starovoitov 
Acked-by: Thomas Graf 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller

ip_tunnels: use tos and ttl fields also for IPv6

2015-08-20T22:42:36+00:00

Rename the ipv4_tos and ipv4_ttl fields to just 'tos' and 'ttl', as they'll
be used with IPv6 tunnels, too.

Signed-off-by: Jiri Benc 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller

ip_tunnels: add IPv6 addresses to ip_tunnel_key

2015-08-20T22:42:36+00:00

Add the IPv6 addresses as an union with IPv4 ones. When using IPv4, the
newly introduced padding after the IPv4 addresses needs to be zeroed out.

Signed-off-by: Jiri Benc 
Acked-by: Thomas Graf 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

ip_tunnels: use offsetofend

2015-08-20T22:42:36+00:00

Signed-off-by: Jiri Benc 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller