net: cls_u32: be more strict about skip-sw flag

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.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files 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;
 }