bareudp: Reverted support to enable & disable rx metadata collection

The commit fe80536 ("bareudp: Added attribute to enable & disable
rx metadata collection") breaks the the original(5.7) default behavior of
bareudp module to collect RX metadadata at the receive. It was added to
avoid the crash at the kernel neighbour subsytem when packet with metadata
from bareudp is processed. But it is no more needed as the
commit 394de11 ("net: Added pointer check for
dst->ops->neigh_lookup in dst_neigh_lookup_skb") solves this crash.

Fixes: fe80536 ("bareudp: Added attribute to enable & disable rx metadata collection")
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/bareudp.rst

@@ -48,7 +48,5 @@ enabled.
 The bareudp device could be used along with OVS or flower filter in TC.
 The OVS or TC flower layer must set the tunnel information in SKB dst field before
 sending packet buffer to the bareudp device for transmission. On reception the
-bareudp device decapsulates the udp header and passes the inner packet to the
-network stack. If RX_COLLECT_METADATA flag is enabled in the device the tunnel
-information will be stored in the SKB dst field before the packet buffer is
-passed to the network stack.
+bareudp device extracts and stores the tunnel information in SKB dst field before
+passing the packet buffer to the network stack.

drivers/net/bareudp.c

@@ -46,7 +46,6 @@ struct bareudp_dev {
 	__be16             port;
 	u16	           sport_min;
 	bool               multi_proto_mode;
-	bool               rx_collect_metadata;
 	struct socket      __rcu *sock;
 	struct list_head   next;        /* bareudp node  on namespace list */
 	struct gro_cells   gro_cells;
@@ -126,14 +125,12 @@ static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 		bareudp->dev->stats.rx_dropped++;
 		goto drop;
 	}
-	if (bareudp->rx_collect_metadata) {
-		tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
-		if (!tun_dst) {
-			bareudp->dev->stats.rx_dropped++;
-			goto drop;
-		}
-		skb_dst_set(skb, &tun_dst->dst);
+	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
+	if (!tun_dst) {
+		bareudp->dev->stats.rx_dropped++;
+		goto drop;
 	}
+	skb_dst_set(skb, &tun_dst->dst);
 	skb->dev = bareudp->dev;
 	oiph = skb_network_header(skb);
 	skb_reset_network_header(skb);
@@ -577,9 +574,6 @@ static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
 		conf->multi_proto_mode = true;
 
-	if (data[IFLA_BAREUDP_RX_COLLECT_METADATA])
-		conf->rx_collect_metadata = true;
-
 	return 0;
 }
 
@@ -617,7 +611,6 @@ static int bareudp_configure(struct net *net, struct net_device *dev,
 	bareudp->ethertype = conf->ethertype;
 	bareudp->sport_min = conf->sport_min;
 	bareudp->multi_proto_mode = conf->multi_proto_mode;
-	bareudp->rx_collect_metadata = conf->rx_collect_metadata;
 
 	err = register_netdevice(dev);
 	if (err)
@@ -676,7 +669,6 @@ static size_t bareudp_get_size(const struct net_device *dev)
 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
-		nla_total_size(0)              +  /* IFLA_BAREUDP_RX_COLLECT_METADATA */
 		0;
 }
 
@@ -693,9 +685,6 @@ static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	if (bareudp->multi_proto_mode &&
 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
 		goto nla_put_failure;
-	if (bareudp->rx_collect_metadata &&
-	    nla_put_flag(skb, IFLA_BAREUDP_RX_COLLECT_METADATA))
-		goto nla_put_failure;
 
 	return 0;
 

include/net/bareudp.h

@@ -12,7 +12,6 @@ struct bareudp_conf {
 	__be16 port;
 	u16 sport_min;
 	bool multi_proto_mode;
-	bool rx_collect_metadata;
 };
 
 struct net_device *bareudp_dev_create(struct net *net, const char *name,

include/uapi/linux/if_link.h

@@ -601,7 +601,6 @@ enum {
 	IFLA_BAREUDP_ETHERTYPE,
 	IFLA_BAREUDP_SRCPORT_MIN,
 	IFLA_BAREUDP_MULTIPROTO_MODE,
-	IFLA_BAREUDP_RX_COLLECT_METADATA,
 	__IFLA_BAREUDP_MAX
 };