From 4a132095dd64fefabdc5dad1cd9e9809b126e582 Mon Sep 17 00:00:00 2001 From: Shannon Nelson Date: Wed, 22 Aug 2018 14:38:10 -0700 Subject: [PATCH] xfrm: allow driver to quietly refuse offload If the "offload" attribute is used to create an IPsec SA and the .xdo_dev_state_add() fails, the SA creation fails. However, if the "offload" attribute is used on a device that doesn't offer it, the attribute is quietly ignored and the SA is created without an offload. Along the same line of that second case, it would be good to have a way for the device to refuse to offload an SA without failing the whole SA creation. This patch adds that feature by allowing the driver to return -EOPNOTSUPP as a signal that the SA may be fine, it just can't be offloaded. This allows the user a little more flexibility in requesting offloads and not needing to know every detail at all times about each specific NIC when trying to create SAs. Signed-off-by: Shannon Nelson Signed-off-by: Steffen Klassert --- Documentation/networking/xfrm_device.txt | 4 ++++ net/xfrm/xfrm_device.c | 6 +++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/xfrm_device.txt b/Documentation/networking/xfrm_device.txt index 50c34ca65efe..267f55b5f54a 100644 --- a/Documentation/networking/xfrm_device.txt +++ b/Documentation/networking/xfrm_device.txt @@ -68,6 +68,10 @@ and an indication of whether it is for Rx or Tx. The driver should - verify the algorithm is supported for offloads - store the SA information (key, salt, target-ip, protocol, etc) - enable the HW offload of the SA + - return status value: + 0 success + -EOPNETSUPP offload not supported, try SW IPsec + other fail the request The driver can also set an offload_handle in the SA, an opaque void pointer that can be used to convey context into the fast-path offload requests. diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c index 5611b7521020..3a1d9d6aefb4 100644 --- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -192,9 +192,13 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, err = dev->xfrmdev_ops->xdo_dev_state_add(x); if (err) { + xso->num_exthdrs = 0; + xso->flags = 0; xso->dev = NULL; dev_put(dev); - return err; + + if (err != -EOPNOTSUPP) + return err; } return 0;