[PATCH net-next 3/4] vxlan: report the drop reason of __iptunnel_pull_header()

[Anton Danilov <littlesmilingcloud@gmail.com>]

vxlan_rcv() reports SKB_DROP_REASON_NOMEM whenever
__iptunnel_pull_header() fails, as the helper used to return -ENOMEM
for any failure. The VXLAN header is already in the linear area at this
point, but the inner Ethernet header of a packet without GPE may not
be, so a packet whose inner frame is shorter than an Ethernet header is
reported as an out of memory condition.

Report the reason __iptunnel_pull_header() now returns instead:
PKT_TOO_SMALL for such a packet, NOMEM when an allocation fails.

Suggested-by: Ido Schimmel <idosch@nvidia.com>
Assisted-by: LLM
Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com>
---
 drivers/net/vxlan/vxlan_core.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 35a47cc27200..0d98e29e2d72 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1743,11 +1743,11 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		raw_proto = true;
 	}
 
-	if (__iptunnel_pull_header(skb, VXLAN_HLEN, protocol, raw_proto,
-				   !net_eq(vxlan->net, dev_net(vxlan->dev)))) {
-		reason = SKB_DROP_REASON_NOMEM;
+	reason = __iptunnel_pull_header(skb, VXLAN_HLEN, protocol, raw_proto,
+					!net_eq(vxlan->net,
+						dev_net(vxlan->dev)));
+	if (reason)
 		goto drop;
-	}
 
 	if (cfg->flags & VXLAN_F_REMCSUM_RX) {
 		reason = vxlan_remcsum(skb, cfg->flags);
-- 
2.47.3