Re: [PATCH net 2/2] net: cls_u32: be more strict about skip-sw flag

[Samudrala, Sridhar]

On 6/6/2016 8:16 AM, Jakub Kicinski wrote:

Return an error if user requested skip-sw and the underlaying
hardware cannot handle tc offloads (or offloads are disabled).

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>

looks good. I think we need similar checks in u32_replace_hw_knode() too.

---
  net/sched/cls_u32.c | 21 +++++++++++----------
  1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index b17e090f2fe1..fe05449537a3 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -457,20 +457,21 @@ static int u32_replace_hw_hnode(struct tcf_proto *tp,
        struct tc_to_netdev offload;
        int err;

+ if (!tc_should_offload(dev, flags))

+               return tc_skip_sw(flags) ? -EINVAL : 0;
+
        offload.type = TC_SETUP_CLSU32;
        offload.cls_u32 = &u32_offload;

- if (tc_should_offload(dev, flags)) {

-               offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
-               offload.cls_u32->hnode.divisor = h->divisor;
-               offload.cls_u32->hnode.handle = h->handle;
-               offload.cls_u32->hnode.prio = h->prio;
+       offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
+       offload.cls_u32->hnode.divisor = h->divisor;
+       offload.cls_u32->hnode.handle = h->handle;
+       offload.cls_u32->hnode.prio = h->prio;

- err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,

-                                                   tp->protocol, &offload);
-               if (tc_skip_sw(flags))
-                       return err;
-       }
+       err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
+                                           tp->protocol, &offload);
+       if (tc_skip_sw(flags))
+               return err;

return 0;

  }