edge: Remove wrong bug warn when processing pending streams

The connection_ap_attach_pending() function processes all pending
streams in the pending_entry_connections list. It first copy the pointer
and then allocates a brand new empty list.

It then iterates over that copy pointer to try to attach entry
connections onto any fitting circuits using
connection_ap_handshake_attach_circuit().

That very function, for onion service, can lead to flagging _all_
streams of the same onion service to be put in state RENDDESC_WAIT from
CIRCUIT_WAIT. By doing so, it also tries to remove them from the
pending_entry_connections but at that point it is already empty.

Problem is that the we are iterating over the previous
pending_entry_connections which contains the streams that have just
changed state and are no longer in CIRCUIT_WAIT.

This lead to this bug warning occuring a lot on busy services:

  May 01 08:55:43.000 [warn] connection_ap_attach_pending(): Bug:
  0x55d8764ae550 is no longer in circuit_wait. Its current state is
  waiting for rendezvous desc. Why is it on pending_entry_connections?
  (on Tor 0.4.4.0-alpha-dev )

This fix is minimal and basically allow a state to be not CIRCUIT_WAIT
and move on to the next one without logging a warning. Because the
pending_entry_connections is emptied before processing, there is no
chance for a streams to be stuck there forever thus it is OK to ignore
streams not in the right state.

Fixes #34083

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/core/or/connection_edge.c b/src/core/or/connection_edge.c
index d4d9d2f759..4228cd6aba 100644
--- a/src/core/or/connection_edge.c
+++ b/src/core/or/connection_edge.c
@@ -1347,11 +1347,10 @@ connection_ap_attach_pending(int retry)
       continue;
     }
     if (conn->state != AP_CONN_STATE_CIRCUIT_WAIT) {
-      log_warn(LD_BUG, "%p is no longer in circuit_wait. Its current state "
-               "is %s. Why is it on pending_entry_connections?",
-               entry_conn,
-               conn_state_to_string(conn->type, conn->state));
-      UNMARK();
+      /* The connection_ap_handshake_attach_circuit() call, for onion service,
+       * can lead to more than one connections in the "pending" list to change
+       * state and so it is OK to get here. Ignore it because this connection
+       * won't be in pending_entry_connections list after this point. */
       continue;
     }