hs: Cleanup logging statement in hs_intropoint.c

One log statement was a warning and has been forgotten. It is triggered for a
successful attempt at introducting from a client.

It has been reported here:
https://lists.torproject.org/pipermail/tor-relays/2017-August/012689.html

Three other log_warn() statement changed to protocol warning because they are
errors that basically can come from the network and thus triggered by anyone.

Fixes #23078.

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

changes/bug23078

@@ -0,0 +1,7 @@
+  o Minor bugfixes (logging, relay):
+    - Remove a log_warn() that has been forgotten when an introduction point
+      successfully established a hidden service prop224 circuit with a client.
+    - Three other log_warn() for an introduction point have been changed to
+      protocol warning because they can be failure from the network and are
+      not relevant to the operator. Fixes bug 23078; bugfix on
+      tor-0.3.0.1-alpha and tor-0.3.0.2-alpha.

src/or/hs_intropoint.c

@@ -190,7 +190,7 @@ handle_verified_establish_intro_cell(or_circuit_t *circ,
   /* Then notify the hidden service that the intro point is established by
      sending an INTRO_ESTABLISHED cell */
   if (hs_intro_send_intro_established_cell(circ)) {
-    log_warn(LD_BUG, "Couldn't send INTRO_ESTABLISHED cell.");
+    log_warn(LD_PROTOCOL, "Couldn't send INTRO_ESTABLISHED cell.");
     return -1;
   }
 
@@ -248,9 +248,6 @@ handle_establish_intro(or_circuit_t *circ, const uint8_t *request,
     goto err;
   }
 
-  log_warn(LD_GENERAL, "Established prop224 intro point on circuit %" PRIu32,
-           circ->p_circ_id);
-
   /* We are done! */
   retval = 0;
   goto done;
@@ -480,7 +477,7 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
   if (relay_send_command_from_edge(CONTROL_CELL_ID, TO_CIRCUIT(service_circ),
                                    RELAY_COMMAND_INTRODUCE2,
                                    (char *) request, request_len, NULL)) {
-    log_warn(LD_REND, "Unable to send INTRODUCE2 cell to the service.");
+    log_warn(LD_PROTOCOL, "Unable to send INTRODUCE2 cell to the service.");
     /* Inform the client that we can't relay the cell. */
     status = HS_INTRO_ACK_STATUS_CANT_RELAY;
     goto send_ack;
@@ -493,8 +490,8 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
  send_ack:
   /* Send INTRODUCE_ACK or INTRODUCE_NACK to client */
   if (send_introduce_ack_cell(client_circ, status) < 0) {
-    log_warn(LD_REND, "Unable to send an INTRODUCE ACK status %d to client.",
-             status);
+    log_warn(LD_PROTOCOL, "Unable to send an INTRODUCE ACK status %d "
+                          "to client.", status);
     /* Circuit has been closed on failure of transmission. */
     goto done;
   }