psample: Encapsulate packet metadata in a struct

Currently, callers of psample_sample_packet() pass three metadata
attributes: Ingress port, egress port and truncated size. Subsequent
patches are going to add more attributes (e.g., egress queue occupancy),
which also need an indication whether they are valid or not.

Encapsulate packet metadata in a struct in order to keep the number of
arguments reasonable.

Signed-off-by: Ido Schimmel <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: idosch

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2217,7 +2217,7 @@ void mlxsw_sp_sample_receive(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = mlxsw_sp->ports[local_port];
 	struct mlxsw_sp_port_sample *sample;
-	u32 size;
+	struct psample_metadata md = {};
 
 	if (unlikely(!mlxsw_sp_port)) {
 		dev_warn_ratelimited(mlxsw_sp->bus_info->dev, "Port %d: sample skb received for non-existent port\n",
@@ -2229,9 +2229,9 @@ void mlxsw_sp_sample_receive(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,
 	sample = rcu_dereference(mlxsw_sp_port->sample);
 	if (!sample)
 		goto out_unlock;
-	size = sample->truncate ? sample->trunc_size : skb->len;
-	psample_sample_packet(sample->psample_group, skb, size,
-			      mlxsw_sp_port->dev->ifindex, 0, sample->rate);
+	md.trunc_size = sample->truncate ? sample->trunc_size : skb->len;
+	md.in_ifindex = mlxsw_sp_port->dev->ifindex;
+	psample_sample_packet(sample->psample_group, skb, sample->rate, &md);
 out_unlock:
 	rcu_read_unlock();
 out:

include/net/psample.h

@@ -14,22 +14,26 @@ struct psample_group {
 	struct rcu_head rcu;
 };
 
+struct psample_metadata {
+	u32 trunc_size;
+	int in_ifindex;
+	int out_ifindex;
+};
+
 struct psample_group *psample_group_get(struct net *net, u32 group_num);
 void psample_group_take(struct psample_group *group);
 void psample_group_put(struct psample_group *group);
 
 #if IS_ENABLED(CONFIG_PSAMPLE)
 
 void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
-			   u32 trunc_size, int in_ifindex, int out_ifindex,
-			   u32 sample_rate);
+			   u32 sample_rate, const struct psample_metadata *md);
 
 #else
 
 static inline void psample_sample_packet(struct psample_group *group,
-					 struct sk_buff *skb, u32 trunc_size,
-					 int in_ifindex, int out_ifindex,
-					 u32 sample_rate)
+					 struct sk_buff *skb, u32 sample_rate,
+					 const struct psample_metadata *md)
 {
 }
 

net/psample/psample.c

@@ -356,9 +356,11 @@ static int psample_tunnel_meta_len(struct ip_tunnel_info *tun_info)
 #endif
 
 void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
-			   u32 trunc_size, int in_ifindex, int out_ifindex,
-			   u32 sample_rate)
+			   u32 sample_rate, const struct psample_metadata *md)
 {
+	int out_ifindex = md->out_ifindex;
+	int in_ifindex = md->in_ifindex;
+	u32 trunc_size = md->trunc_size;
 #ifdef CONFIG_INET
 	struct ip_tunnel_info *tun_info;
 #endif

net/sched/act_sample.c

@@ -158,10 +158,8 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
 {
 	struct tcf_sample *s = to_sample(a);
 	struct psample_group *psample_group;
+	struct psample_metadata md = {};
 	int retval;
-	int size;
-	int iif;
-	int oif;
 
 	tcf_lastuse_update(&s->tcf_tm);
 	bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
@@ -172,20 +170,18 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
 	/* randomly sample packets according to rate */
 	if (psample_group && (prandom_u32() % s->rate == 0)) {
 		if (!skb_at_tc_ingress(skb)) {
-			iif = skb->skb_iif;
-			oif = skb->dev->ifindex;
+			md.in_ifindex = skb->skb_iif;
+			md.out_ifindex = skb->dev->ifindex;
 		} else {
-			iif = skb->dev->ifindex;
-			oif = 0;
+			md.in_ifindex = skb->dev->ifindex;
 		}
 
 		/* on ingress, the mac header gets popped, so push it back */
 		if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
 			skb_push(skb, skb->mac_len);
 
-		size = s->truncate ? s->trunc_size : skb->len;
-		psample_sample_packet(psample_group, skb, size, iif, oif,
-				      s->rate);
+		md.trunc_size = s->truncate ? s->trunc_size : skb->len;
+		psample_sample_packet(psample_group, skb, s->rate, &md);
 
 		if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
 			skb_pull(skb, skb->mac_len);