Linux Ethernet Bridging - Jan 2021 - [Bridge] [PATCH v2 net-next] net: bridge: check vlan with eth_type_vlan() method

From: Menglong Dong <dong.menglong at zte.com.cn>

Replace some checks for ETH_P_8021Q and ETH_P_8021AD with
eth_type_vlan().

Signed-off-by: Menglong Dong <dong.menglong at zte.com.cn>
---
v2:
- use eth_type_vlan() in br_validate() and __br_vlan_set_proto()
  too.
---
 net/bridge/br_forward.c |  3 +--
 net/bridge/br_netlink.c | 11 +++--------
 net/bridge/br_vlan.c    |  2 +-
 3 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index e28ffadd1371..6e9b049ae521 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -39,8 +39,7 @@ int br_dev_queue_push_xmit(struct net *net, struct sock *sk,
struct sk_buff *skb
 	br_drop_fake_rtable(skb);
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
-	    (skb->protocol == htons(ETH_P_8021Q) ||
-	     skb->protocol == htons(ETH_P_8021AD))) {
+	    eth_type_vlan(skb->protocol)) {
 		int depth;
 
 		if (!__vlan_get_protocol(skb, skb->protocol, &depth))
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 49700ce0e919..15cfcad846c5 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1096,14 +1096,9 @@ static int br_validate(struct nlattr *tb[], struct nlattr
*data[],
 		return 0;
 
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-	if (data[IFLA_BR_VLAN_PROTOCOL]) {
-		switch (nla_get_be16(data[IFLA_BR_VLAN_PROTOCOL])) {
-		case htons(ETH_P_8021Q):
-		case htons(ETH_P_8021AD):
-			break;
-		default:
-			return -EPROTONOSUPPORT;
-		}
+	if (data[IFLA_BR_VLAN_PROTOCOL] &&
+	    !eth_type_vlan(nla_get_be16(data[IFLA_BR_VLAN_PROTOCOL]))) {
+		return -EPROTONOSUPPORT;
 	}
 
 	if (data[IFLA_BR_VLAN_DEFAULT_PVID]) {
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 701cad646b20..24660fe33545 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -917,7 +917,7 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 
 int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
 {
-	if (val != ETH_P_8021Q && val != ETH_P_8021AD)
+	if (!eth_type_vlan(val))
 		return -EPROTONOSUPPORT;
 
 	return __br_vlan_set_proto(br, htons(val));
-- 
2.25.1

On Thu, 14 Jan 2021 18:23:44 -0800 menglong8.dong at gmail.com
wrote:
> From: Menglong Dong <dong.menglong at zte.com.cn>
> 
> Replace some checks for ETH_P_8021Q and ETH_P_8021AD with
> eth_type_vlan().
> 
> Signed-off-by: Menglong Dong <dong.menglong at zte.com.cn>
This adds a new warning when built with W=1 C=1:

net/bridge/br_vlan.c:920:28: warning: incorrect type in argument 1 (different
base types)
net/bridge/br_vlan.c:920:28:    expected restricted __be16 [usertype] ethertype
net/bridge/br_vlan.c:920:28:    got unsigned long val