Re: [PATCH net v2 0/3] Tunneling fixes

[Juerg Haefliger]

> This series fixes a problem that was reported where encapsulated packets
> do not have their encapsulation offload markers stripped off when being
> decapsulated. This causes a significant performance drop if the packets
> are later retransmitted.
>
> Fixing this revealed two other bugs which are also addressed as prerequisites:
>  * GRO can aggregate packets for multiple layers of encapsulation which the
>stack cannot properly handle.
>  * IPIP packets which are combined by GRO are not marked properly with their
>GSO type.
>
> Note that this is based off the net-next tree as the current target for
> bug fixes.

I need to backport this series to the 4.4 kernel to fix a performance issue 
we're seeing. The series
applies but commit a09a4c8dd1ec (tunnels: Remove encapsulation offloads on 
decap) breaks compilation
when CONFIG_IPV6_SIT is enabled. This is because the patch uses 
iptunnel_pull_header() whose usage
changed with commit 7f290c94352e (iptunnel: scrub packet in 
iptunnel_pull_header) which is not in 4.4.

7f290c94352e seems to be a cleanup patch which also requires c9e78efb6f66 
(vxlan: move vxlan device
lookup before iptunnel_pull_header) and potentially others. Rather than pulling 
in a slew of cleanup
patches, I was wondering if the following from commit a09a4c8dd1ec can be 
rewritten without using
the 'new' iptunnel_pull_header() function:

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index f45b8ffc2840..83384308d032 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -681,14 +681,16 @@ static int ipip6_rcv(struct sk_buff *skb)
skb->mac_header = skb->network_header;
skb_reset_network_header(skb);
IPCB(skb)->flags = 0;
-   skb->protocol = htons(ETH_P_IPV6);
+   skb->dev = tunnel->dev;

if (packet_is_spoofed(skb, iph, tunnel)) {
tunnel->dev->stats.rx_errors++;
goto out;
}

-   __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
+   if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
+   !net_eq(tunnel->net, dev_net(tunnel->dev
+   goto out;


Thanks
...Juerg


> v2: No code changes, just additional information in commit messages and
> a new cover letter.
>
> Jesse Gross (3):
>   ipip: Properly mark ipip GRO packets as encapsulated.
>   tunnels: Don't apply GRO to multiple layers of encapsulation.
>   tunnels: Remove encapsulation offloads on decap.
>
>  include/linux/netdevice.h |  4 ++--
>  include/net/ip_tunnels.h  | 16 
>  net/core/dev.c|  2 +-
>  net/ipv4/af_inet.c| 24 ++--
>  net/ipv4/fou.c| 13 +++--
>  net/ipv4/gre_offload.c|  5 +
>  net/ipv4/ip_tunnel_core.c |  3 ++-
>  net/ipv4/udp_offload.c|  6 +++---
>  net/ipv6/ip6_offload.c| 15 ++-
>  net/ipv6/sit.c|  6 --
>  10 files changed, 80 insertions(+), 14 deletions(-)



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Re: [PATCH net v2 0/3] Tunneling fixes

[David Miller]

From: Jesse Gross 
Date: Sat, 19 Mar 2016 09:31:59 -0700

> This series fixes a problem that was reported where encapsulated packets
> do not have their encapsulation offload markers stripped off when being
> decapsulated. This causes a significant performance drop if the packets
> are later retransmitted.
> 
> Fixing this revealed two other bugs which are also addressed as prerequisites:
>  * GRO can aggregate packets for multiple layers of encapsulation which the
>stack cannot properly handle.
>  * IPIP packets which are combined by GRO are not marked properly with their
>GSO type.
> 
> Note that this is based off the net-next tree as the current target for
> bug fixes.
> 
> v2: No code changes, just additional information in commit messages and
> a new cover letter.

Applied, thanks for respinning this Jesse.

[PATCH net v2 0/3] Tunneling fixes

[Jesse Gross]

This series fixes a problem that was reported where encapsulated packets
do not have their encapsulation offload markers stripped off when being
decapsulated. This causes a significant performance drop if the packets
are later retransmitted.

Fixing this revealed two other bugs which are also addressed as prerequisites:
 * GRO can aggregate packets for multiple layers of encapsulation which the
   stack cannot properly handle.
 * IPIP packets which are combined by GRO are not marked properly with their
   GSO type.

Note that this is based off the net-next tree as the current target for
bug fixes.

v2: No code changes, just additional information in commit messages and
a new cover letter.

Jesse Gross (3):
  ipip: Properly mark ipip GRO packets as encapsulated.
  tunnels: Don't apply GRO to multiple layers of encapsulation.
  tunnels: Remove encapsulation offloads on decap.

 include/linux/netdevice.h |  4 ++--
 include/net/ip_tunnels.h  | 16 
 net/core/dev.c|  2 +-
 net/ipv4/af_inet.c| 24 ++--
 net/ipv4/fou.c| 13 +++--
 net/ipv4/gre_offload.c|  5 +
 net/ipv4/ip_tunnel_core.c |  3 ++-
 net/ipv4/udp_offload.c|  6 +++---
 net/ipv6/ip6_offload.c| 15 ++-
 net/ipv6/sit.c|  6 --
 10 files changed, 80 insertions(+), 14 deletions(-)

-- 
2.5.0