[PATCH net-next v6 07/12] net: vxlan: make vxlan_set_mac() return drop reasons

From: Menglong Dong
Date: Tue Oct 08 2024 - 10:27:58 EST


Change the return type of vxlan_set_mac() from bool to enum
skb_drop_reason. In this commit, the drop reason
"SKB_DROP_REASON_LOCAL_MAC" is introduced for the case that the source
mac of the packet is a local mac.

Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
---
v5:
- modify the document of SKB_DROP_REASON_LOCAL_MAC
v3:
- adjust the call of vxlan_set_mac()
- add SKB_DROP_REASON_LOCAL_MAC
---
drivers/net/vxlan/vxlan_core.c | 19 ++++++++++---------
include/net/dropreason-core.h | 6 ++++++
2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 1a81a3957327..41191a28252a 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1609,9 +1609,9 @@ 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;
@@ -1622,7 +1622,7 @@ 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 SKB_DROP_REASON_LOCAL_MAC;

/* Get address from the outer IP header */
if (vxlan_get_sk_family(vs) == AF_INET) {
@@ -1635,11 +1635,11 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
#endif
}

- if ((vxlan->cfg.flags & VXLAN_F_LEARN) &&
- vxlan_snoop(skb->dev, &saddr, eth_hdr(skb)->h_source, ifindex, vni))
- return false;
+ if (!(vxlan->cfg.flags & VXLAN_F_LEARN))
+ return SKB_NOT_DROPPED_YET;

- return true;
+ return vxlan_snoop(skb->dev, &saddr, eth_hdr(skb)->h_source,
+ ifindex, vni);
}

static bool vxlan_ecn_decapsulate(struct vxlan_sock *vs, void *oiph,
@@ -1774,7 +1774,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
}

if (!raw_proto) {
- if (!vxlan_set_mac(vxlan, vs, skb, vni))
+ reason = vxlan_set_mac(vxlan, vs, skb, vni);
+ if (reason)
goto drop;
} else {
skb_reset_mac_header(skb);
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 1cb8d7c953be..fbf92d442c1b 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -97,6 +97,7 @@
FN(MAC_INVALID_SOURCE) \
FN(VXLAN_ENTRY_EXISTS) \
FN(IP_TUNNEL_ECN) \
+ FN(LOCAL_MAC) \
FNe(MAX)

/**
@@ -443,6 +444,11 @@ enum skb_drop_reason {
* RFC 6040 4.2, see __INET_ECN_decapsulate() for detail.
*/
SKB_DROP_REASON_IP_TUNNEL_ECN,
+ /**
+ * @SKB_DROP_REASON_LOCAL_MAC: the source MAC address is equal to
+ * the MAC address of the local netdev.
+ */
+ SKB_DROP_REASON_LOCAL_MAC,
/**
* @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which
* shouldn't be used as a real 'reason' - only for tracing code gen
--
2.39.5