diff options
| author | Cosmin Ratiu <cratiu@nvidia.com> | 2025-04-11 10:49:55 +0300 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2025-04-16 11:01:32 +0200 |
| commit | d53dda291bbd993a29b84d358d282076e3d01506 (patch) | |
| tree | 4e15f3989cd1080f48f3917ee98a96145577fa80 | |
| parent | 25ac138f58e7d5c8bffa31e8891418d2819180c4 (diff) | |
xfrm: Remove unneeded device check from validate_xmit_xfrm
validate_xmit_xfrm checks whether a packet already passed through it on
the master device (xso.dev) and skips processing the skb again on the
slave device (xso.real_dev).
This check was added in commit [1] to avoid tx packets on a bond device
pass through xfrm twice and get two sets of headers, but the check was
soon obsoleted by commit [2], which was added around the same time to
fix a similar but unrelated problem. Commit [3] set XFRM_XMIT only when
packets are hw offloaded.
xso.dev is usually equal to xso.real_dev, unless bonding is used, in
which case the bonding driver uses xso.real_dev to manage offloaded xfrm
states.
Since commit [3], the check added in commit [1] is unused on all cases,
since packets going through validate_xmit_xfrm twice bail out on the
check added in commit [2]. Here's a breakdown of relevant scenarios:
1. ESP offload off: validate_xmit_xfrm returns early on !xo.
2. ESP offload on, no bond: skb->dev == xso.real_dev == xso.dev.
3. ESP offload on, bond, xs on bond dev: 1st pass adds XFRM_XMIT, 2nd
pass returns early on XFRM_XMIT.
3. ESP offload on, bond, xs on slave dev: 1st pass returns early on
!xo, 2nd pass adds XFRM_XMIT.
4. ESP offload on, bond, xs on both bond AND slave dev: only 1 offload
possible in secpath. Either 1st pass adds XFRM_XMIT and 2nd pass returns
early on XFRM_XMIT, or 1st pass is sw and returns early on !xo.
6. ESP offload on, crypto fallback triggered in esp_xmit/esp6_xmit: 1st
pass does sw crypto & secpath_reset, 2nd pass returns on !xo.
This commit removes the unnecessary check, so xso.real_dev becomes what
it is in practice: a private field managed by bonding driver.
The check immediately below that can be simplified as well.
[1] commit 272c2330adc9 ("xfrm: bail early on slave pass over skb")
[2] commit 94579ac3f6d0 ("xfrm: Fix double ESP trailer insertion in
IPsec crypto offload.")
[3] commit c7dbf4c08868 ("xfrm: Provide private skb extensions for
segmented and hw offloaded ESP packets")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
| -rw-r--r-- | net/xfrm/xfrm_device.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c index 4f4165ff738d..0be5f7ffd019 100644 --- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -145,10 +145,6 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur return NULL; } - /* This skb was already validated on the upper/virtual dev */ - if ((x->xso.dev != dev) && (x->xso.real_dev == dev)) - return skb; - local_irq_save(flags); sd = this_cpu_ptr(&softnet_data); err = !skb_queue_empty(&sd->xfrm_backlog); @@ -159,8 +155,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur return skb; } - if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) || - unlikely(xmit_xfrm_check_overflow(skb)))) { + if (skb_is_gso(skb) && unlikely(xmit_xfrm_check_overflow(skb))) { struct sk_buff *segs; /* Packet got rerouted, fixup features and segment it. */ |