hs: Get rid of duplicate hs_cell_introd_ack_status_t

This enum was the exact same as hs_intro_ack_status_t that was removed at the
previous commit. It was used client side when parsing the INTRODUCE_ACK cell.

Now, the entire code dealing with the INTRODUCE_ACK cell (both sending and
receiving) have been modified to all use the same ABI defined in the trunnel
introduce1 file.

Finally, the client will default to the normal behavior when receiving an
unknown NACK status code which is to note down that we've failed and re-extend
to the next intro point. This way, unknown status code won't trigger a
different behavior client side.

Part of #30454.

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

src/or/hs_cell.c

@@ -881,9 +881,9 @@ hs_cell_parse_introduce_ack(const uint8_t *payload, size_t payload_len)
    * do a special case. */
   if (payload_len <= 1) {
     if (payload_len == 0) {
-      ret = HS_CELL_INTRO_ACK_SUCCESS;
+      ret = TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS;
     } else {
-      ret = HS_CELL_INTRO_ACK_FAILURE;
+      ret = TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID;
     }
     goto end;
   }

src/or/hs_cell.h

@@ -16,14 +16,6 @@
  * 3.2.2 of the specification). Below this value, the cell must be padded. */
 #define HS_CELL_INTRODUCE1_MIN_SIZE 246
 
-/* Status code of an INTRODUCE_ACK cell. */
-typedef enum {
-  HS_CELL_INTRO_ACK_SUCCESS = 0x0000, /* Cell relayed to service. */
-  HS_CELL_INTRO_ACK_FAILURE = 0x0001, /* Service ID not recognized */
-  HS_CELL_INTRO_ACK_BADFMT  = 0x0002, /* Bad message format */
-  HS_CELL_INTRO_ACK_NORELAY = 0x0003, /* Can't relay cell to service */
-} hs_cell_introd_ack_status_t;
-
 /* Onion key type found in the INTRODUCE1 cell. */
 typedef enum {
   HS_CELL_ONION_KEY_TYPE_NTOR = 1,

src/or/hs_client.c

@@ -35,6 +35,8 @@
 #include "router.h"
 #include "routerset.h"
 
+#include "trunnel/hs/cell_introduce1.h"
+
 /* Return a human-readable string for the client fetch status code. */
 static const char *
 fetch_status_to_string(hs_client_fetch_status_t status)
@@ -1018,23 +1020,21 @@ handle_introduce_ack(origin_circuit_t *circ, const uint8_t *payload,
 
   status = hs_cell_parse_introduce_ack(payload, payload_len);
   switch (status) {
-  case HS_CELL_INTRO_ACK_SUCCESS:
+  case TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS:
     ret = 0;
     handle_introduce_ack_success(circ);
     goto end;
-  case HS_CELL_INTRO_ACK_FAILURE:
+  case TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID:
-  case HS_CELL_INTRO_ACK_BADFMT:
+  case TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT:
-  case HS_CELL_INTRO_ACK_NORELAY:
+  /* It is possible that the intro point can send us an unknown status code
+   * for the NACK that we do not know about like a new code for instance.
+   * Just fallthrough so we can note down the NACK and re-extend. */
+  default:
     handle_introduce_ack_bad(circ, status);
     /* We are going to see if we have to close the circuits (IP and RP) or we
      * can re-extend to a new intro point. */
     ret = close_or_reextend_intro_circ(circ);
     break;
-  default:
-    log_info(LD_PROTOCOL, "Unknown INTRODUCE_ACK status code %u from %s",
-        status,
-        safe_str_client(extend_info_describe(circ->build_state->chosen_exit)));
-    break;
   }
 
  end: