[PATCH net-next v2 06/12] net: vxlan: make vxlan_set_mac() return drop reasons

[Menglong Dong]

Change the return type of vxlan_set_mac() from bool to enum
skb_drop_reason. In this commit, two drop reasons are introduced:

  VXLAN_DROP_INVALID_SMAC
  VXLAN_DROP_ENTRY_EXISTS

To make it easier to document the reasons in drivers/net/vxlan/drop.h,
we don't define the enum vxlan_drop_reason with the macro
VXLAN_DROP_REASONS(), but hand by hand.

Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
 drivers/net/vxlan/drop.h       |  9 +++++++++
 drivers/net/vxlan/vxlan_core.c | 12 ++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/net/vxlan/drop.h b/drivers/net/vxlan/drop.h
index 6bcc6894fbbd..876b4a9de92f 100644
--- a/drivers/net/vxlan/drop.h
+++ b/drivers/net/vxlan/drop.h
@@ -9,11 +9,20 @@
 #include <net/dropreason.h>
 
 #define VXLAN_DROP_REASONS(R)			\
+	R(VXLAN_DROP_INVALID_SMAC)		\
+	R(VXLAN_DROP_ENTRY_EXISTS)		\
 	/* deliberate comment for trailing \ */
 
 enum vxlan_drop_reason {
 	__VXLAN_DROP_REASON = SKB_DROP_REASON_SUBSYS_VXLAN <<
 				SKB_DROP_REASON_SUBSYS_SHIFT,
+	/** @VXLAN_DROP_INVALID_SMAC: source mac is invalid */
+	VXLAN_DROP_INVALID_SMAC,
+	/**
+	 * @VXLAN_DROP_ENTRY_EXISTS: trying to migrate a static entry or
+	 * one pointing to a nexthop
+	 */
+	VXLAN_DROP_ENTRY_EXISTS,
 };
 
 static inline void
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 76b217d166ef..58c175432a15 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1607,9 +1607,9 @@ static void vxlan_parse_gbp_hdr(struct vxlanhdr *unparsed,
 	unparsed->vx_flags &= ~VXLAN_GBP_USED_BITS;
 }
 
-static bool vxlan_set_mac(struct vxlan_dev *vxlan,
-			  struct vxlan_sock *vs,
-			  struct sk_buff *skb, __be32 vni)
+static enum skb_drop_reason vxlan_set_mac(struct vxlan_dev *vxlan,
+					  struct vxlan_sock *vs,
+					  struct sk_buff *skb, __be32 vni)
 {
 	union vxlan_addr saddr;
 	u32 ifindex = skb->dev->ifindex;
@@ -1620,7 +1620,7 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
 
 	/* Ignore packet loops (and multicast echo) */
 	if (ether_addr_equal(eth_hdr(skb)->h_source, vxlan->dev->dev_addr))
-		return false;
+		return (u32)VXLAN_DROP_INVALID_SMAC;
 
 	/* Get address from the outer IP header */
 	if (vxlan_get_sk_family(vs) == AF_INET) {
@@ -1635,9 +1635,9 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
 
 	if ((vxlan->cfg.flags & VXLAN_F_LEARN) &&
 	    vxlan_snoop(skb->dev, &saddr, eth_hdr(skb)->h_source, ifindex, vni))
-		return false;
+		return (u32)VXLAN_DROP_ENTRY_EXISTS;
 
-	return true;
+	return (u32)SKB_NOT_DROPPED_YET;
 }
 
 static bool vxlan_ecn_decapsulate(struct vxlan_sock *vs, void *oiph,
-- 
2.39.2