rxrpc: Improve skb tracing

Improve sk_buff tracing within AF_RXRPC by the following means:

 (1) Use an enum to note the event type rather than plain integers and use
     an array of event names rather than a big multi ?: list.

 (2) Distinguish Rx from Tx packets and account them separately.  This
     requires the call phase to be tracked so that we know what we might
     find in rxtx_buffer[].

 (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the
     event type.

 (4) A pair of 'rotate' events are added to indicate packets that are about
     to be rotated out of the Rx and Tx windows.

 (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for
     packet loss injection recording.

Signed-off-by: David Howells <[email protected]>
 
diff --git a/net/rxrpc/local_event.c b/net/rxrpc/local_event.c
index f073e93..190f68b 100644
--- a/net/rxrpc/local_event.c
+++ b/net/rxrpc/local_event.c
@@ -90,7 +90,7 @@
 	if (skb) {
 		struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 
-		rxrpc_see_skb(skb);
+		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 		_debug("{%d},{%u}", local->debug_id, sp->hdr.type);
 
 		switch (sp->hdr.type) {
@@ -107,7 +107,7 @@
 			break;
 		}
 
-		rxrpc_free_skb(skb);
+		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 	}
 
 	_leave("");