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Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 8e6f22961206..30a1603a7225 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4863,7 +4863,10 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
}
/* When doing generic XDP we have to bypass the qdisc layer and the
- * network taps in order to match in-driver-XDP behavior.
+ * network taps in order to match in-driver-XDP behavior. This also means
+ * that XDP packets are able to starve other packets going through a qdisc,
+ * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
+ * queues, so they do not have this starvation issue.
*/
void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
{
@@ -4875,7 +4878,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
txq = netdev_core_pick_tx(dev, skb, NULL);
cpu = smp_processor_id();
HARD_TX_LOCK(dev, txq, cpu);
- if (!netif_xmit_stopped(txq)) {
+ if (!netif_xmit_frozen_or_drv_stopped(txq)) {
rc = netdev_start_xmit(skb, dev, txq, 0);
if (dev_xmit_complete(rc))
free_skb = false;
@@ -4883,6 +4886,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
HARD_TX_UNLOCK(dev, txq);
if (free_skb) {
trace_xdp_exception(dev, xdp_prog, XDP_TX);
+ dev_core_stats_tx_dropped_inc(dev);
kfree_skb(skb);
}
}