tracing: update log_p2p_traffic.bt bpftrace script

bpftrace doesn't have any functions as of writing this commit, so we
have to do a ternary lookup hack that introduces a bit of code
duplication.

Alternatively you could try to use a bpf map, but this uses a lot of
stack space in bpftrace which makes it harder to run this script
effectively.

Signed-off-by: William Casarin <jb55@jb55.com>

contrib/tracing/log_p2p_traffic.bt

@@ -2,14 +2,15 @@
 
 BEGIN
 {
-  printf("Logging P2P traffic\n")
+  printf("Logging P2P traffic\n");
 }
 
 usdt:./src/bitcoind:net:inbound_message
 {
   $peer_id = (int64) arg0;
   $peer_addr = str(arg1);
-  $peer_type = str(arg2);
+  $ct = (uint32)arg2;
+  $peer_type = ($ct == 0 ? "inbound":($ct == 1 ? "outbound-full-relay":($ct == 2 ? "manual":($ct == 3 ? "feeler":($ct == 4 ? "block-relay":($ct == 5 ? "addr-fetch":"unknown"))))));
   $msg_type = str(arg3);
   $msg_len = arg4;
   printf("inbound '%s' msg from peer %d (%s, %s) with %d bytes\n", $msg_type, $peer_id, $peer_type, $peer_addr, $msg_len);
@@ -19,7 +20,8 @@ usdt:./src/bitcoind:net:outbound_message
 {
   $peer_id = (int64) arg0;
   $peer_addr = str(arg1);
-  $peer_type = str(arg2);
+  $ct = (uint32)arg2;
+  $peer_type = ($ct == 0 ? "inbound":($ct == 1 ? "outbound-full-relay":($ct == 2 ? "manual":($ct == 3 ? "feeler":($ct == 4 ? "block-relay":($ct == 5 ? "addr-fetch":"unknown"))))));
   $msg_type = str(arg3);
   $msg_len = arg4;