Make vxlan_remcsum() support skb drop reasons by changing the return
value type of it from bool to enum skb_drop_reason.

The only drop reason in vxlan_remcsum() comes from pskb_may_pull_reason(),
so we just return it.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
v3:
- add a empty newline before return, as Alexander advised
- adjust the call of vxlan_remcsum()
---
 drivers/net/vxlan/vxlan_core.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 04c56f952f29..03c82c945b33 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1551,9 +1551,11 @@ static void vxlan_sock_release(struct vxlan_dev *vxlan)
 #endif
 }
 
-static bool vxlan_remcsum(struct vxlanhdr *unparsed,
-			  struct sk_buff *skb, u32 vxflags)
+static enum skb_drop_reason vxlan_remcsum(struct vxlanhdr *unparsed,
+					  struct sk_buff *skb,
+					  u32 vxflags)
 {
+	enum skb_drop_reason reason;
 	size_t start, offset;
 
 	if (!(unparsed->vx_flags & VXLAN_HF_RCO) || skb->remcsum_offload)
@@ -1562,15 +1564,17 @@ static bool vxlan_remcsum(struct vxlanhdr *unparsed,
 	start = vxlan_rco_start(unparsed->vx_vni);
 	offset = start + vxlan_rco_offset(unparsed->vx_vni);
 
-	if (!pskb_may_pull(skb, offset + sizeof(u16)))
-		return false;
+	reason = pskb_may_pull_reason(skb, offset + sizeof(u16));
+	if (reason)
+		return reason;
 
 	skb_remcsum_process(skb, (void *)(vxlan_hdr(skb) + 1), start, offset,
 			    !!(vxflags & VXLAN_F_REMCSUM_NOPARTIAL));
 out:
 	unparsed->vx_flags &= ~VXLAN_HF_RCO;
 	unparsed->vx_vni &= VXLAN_VNI_MASK;
-	return true;
+
+	return SKB_NOT_DROPPED_YET;
 }
 
 static void vxlan_parse_gbp_hdr(struct vxlanhdr *unparsed,
@@ -1723,9 +1727,11 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 	}
 
-	if (vs->flags & VXLAN_F_REMCSUM_RX)
-		if (unlikely(!vxlan_remcsum(&unparsed, skb, vs->flags)))
+	if (vs->flags & VXLAN_F_REMCSUM_RX) {
+		reason = vxlan_remcsum(&unparsed, skb, vs->flags);
+		if (unlikely(reason))
 			goto drop;
+	}
 
 	if (vxlan_collect_metadata(vs)) {
 		IP_TUNNEL_DECLARE_FLAGS(flags) = { };
-- 
2.39.2