BMC/Intel-BMC/linux.git/net/ipv4/gre_offload.c, branch dev-4.6

GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU

2016-04-07T20:56:33+00:00

This patch fixes an issue I found in which we were dropping frames if we had enabled checksums on GRE headers that were encapsulated by either FOU or GUE. Without this patch I was barely able to get 1 Gb/s of throughput. With this patch applied I am now at least getting around 6 Gb/s. The issue is due to the fact that with FOU or GUE applied we do not provide a transport offset pointing to the GRE header, nor do we offload it in software as the GRE header is completely skipped by GSO and treated like a VXLAN or GENEVE type header. As such we need to prevent the stack from generating it and also prevent GRE from generating it via any interface we create. Fixes: c3483384ee511 ("gro: Allow tunnel stacking in the case of FOU/GUE") Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

net: Reset encap_level to avoid resetting features on inner IP headers

2016-03-23T18:19:08+00:00

This patch corrects an oversight in which we were allowing the encap_level value to pass from the outer headers to the inner headers. As a result we were incorrectly identifying UDP or GRE tunnels as also making use of ipip or sit when the second header actually represented a tunnel encapsulated in either a UDP or GRE tunnel which already had the features masked. Fixes: 76443456227097179c1482 ("net: Move GSO csum into SKB_GSO_CB") Reported-by: Tom Herbert Signed-off-by: Alexander Duyck Acked-by: Tom Herbert Signed-off-by: David S. Miller

tunnels: Don't apply GRO to multiple layers of encapsulation.

2016-03-20T20:33:40+00:00

When drivers express support for TSO of encapsulated packets, they only mean that they can do it for one layer of encapsulation. Supporting additional levels would mean updating, at a minimum, more IP length fields and they are unaware of this. No encapsulation device expresses support for handling offloaded encapsulated packets, so we won't generate these types of frames in the transmit path. However, GRO doesn't have a check for multiple levels of encapsulation and will attempt to build them. UDP tunnel GRO actually does prevent this situation but it only handles multiple UDP tunnels stacked on top of each other. This generalizes that solution to prevent any kind of tunnel stacking that would cause problems. Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack") Signed-off-by: Jesse Gross Signed-off-by: David S. Miller

gro: Defer clearing of flush bit in tunnel paths

2016-03-13T19:01:00+00:00

This patch updates the GRO handlers for GRE, VXLAN, GENEVE, and FOU so that we do not clear the flush bit until after we have called the next level GRO handler. Previously this was being cleared before parsing through the list of frames, however this resulted in several paths where either the bit needed to be reset but wasn't as in the case of FOU, or cases where it was being set as in GENEVE. By just deferring the clearing of the bit until after the next level protocol has been parsed we can avoid any unnecessary bit twiddling and avoid bugs. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

GSO: Provide software checksum of tunneled UDP fragmentation offload

2016-02-26T19:23:35+00:00

On reviewing the code I realized that GRE and UDP tunnels could cause a kernel panic if we used GSO to segment a large UDP frame that was sent through the tunnel with an outer checksum and hardware offloads were not available. In order to correct this we need to update the feature flags that are passed to the skb_segment function so that in the event of UDP fragmentation being requested for the inner header the segmentation function will correctly generate the checksum for the payload if we cannot segment the outer header. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

gre: Use inner_proto to obtain inner header protocol

2016-02-11T13:55:34+00:00

Instead of parsing headers to determine the inner protocol we can just pull the value from inner_proto. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

gre: Use GSO flags to determine csum need instead of GRE flags

2016-02-11T13:55:34+00:00

This patch updates the gre checksum path to follow something much closer to the UDP checksum path. By doing this we can avoid needing to do as much header inspection and can just make use of the fields we were already reading in the sk_buff structure. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

net: Move skb_has_shared_frag check out of GRE code and into segmentation

2016-02-11T13:55:34+00:00

The call skb_has_shared_frag is used in the GRE path and skb_checksum_help to verify that no frags can be modified by an external entity. This check really doesn't belong in the GRE path but in the skb_segment function itself. This way any protocol that might be segmented will be performing this check before attempting to offload a checksum to software. Signed-off-by: Alexander Duyck Acked-by: Tom Herbert Signed-off-by: David S. Miller

net: Drop unecessary enc_features variable from tunnel segmentation functions

2016-02-11T13:55:33+00:00

The enc_features variable isn't necessary since features isn't used anywhere after we create enc_features so instead just use a destructive AND on features itself and save ourselves the variable declaration. Signed-off-by: Alexander Duyck Acked-by: Tom Herbert Signed-off-by: David S. Miller

ipv6: gre: support SIT encapsulation

2015-10-27T05:01:18+00:00

gre_gso_segment() chokes if SIT frames were aggregated by GRO engine. Fixes: 61c1db7fae21e ("ipv6: sit: add GSO/TSO support") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller