hs: Define INTRODUCE_ACK status code in trunnel

Remove the hs_intro_ack_status_t enum and move the value into trunnel. Only
use these values from now on in the intro point code.

Interestingly enough, the client side also re-define these values in hs_cell.h
with the hs_cell_introd_ack_status_t enum. Next commit will fix that and force
to use the trunnel ABI.

Part of #30454

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

src/or/hs_intropoint.c

@@ -336,7 +336,7 @@ hs_intro_received_establish_intro(or_circuit_t *circ, const uint8_t *request,
  * Return 0 on success else a negative value on error which will close the
  * circuit. */
 static int
-send_introduce_ack_cell(or_circuit_t *circ, hs_intro_ack_status_t status)
+send_introduce_ack_cell(or_circuit_t *circ, uint16_t status)
 {
   int ret = -1;
   uint8_t *encoded_cell = NULL;
@@ -433,7 +433,7 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
   int ret = -1;
   or_circuit_t *service_circ;
   trn_cell_introduce1_t *parsed_cell;
-  hs_intro_ack_status_t status = HS_INTRO_ACK_STATUS_SUCCESS;
+  uint16_t status = TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS;
 
   tor_assert(client_circ);
   tor_assert(request);
@@ -448,14 +448,14 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
            "Rejecting %s INTRODUCE1 cell. Responding with NACK.",
            cell_size == -1 ? "invalid" : "truncated");
     /* Inform client that the INTRODUCE1 has a bad format. */
-    status = HS_INTRO_ACK_STATUS_BAD_FORMAT;
+    status = TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT;
     goto send_ack;
   }
 
   /* Once parsed validate the cell format. */
   if (validate_introduce1_parsed_cell(parsed_cell) < 0) {
     /* Inform client that the INTRODUCE1 has bad format. */
-    status = HS_INTRO_ACK_STATUS_BAD_FORMAT;
+    status = TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT;
     goto send_ack;
   }
 
@@ -472,7 +472,7 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
                         "Responding with NACK.",
                safe_str(b64_key), client_circ->p_circ_id);
       /* Inform the client that we don't know the requested service ID. */
-      status = HS_INTRO_ACK_STATUS_UNKNOWN_ID;
+      status = TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID;
       goto send_ack;
     }
   }
@@ -485,12 +485,12 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
     log_warn(LD_PROTOCOL, "Unable to send INTRODUCE2 cell to the service.");
     /* Inform the client that we can't relay the cell. Use the unknown ID
      * status code since it means that we do not know the service. */
-    status = HS_INTRO_ACK_STATUS_UNKNOWN_ID;
+    status = TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID;
     goto send_ack;
   }
 
   /* Success! Send an INTRODUCE_ACK success status onto the client circuit. */
-  status = HS_INTRO_ACK_STATUS_SUCCESS;
+  status = TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS;
   ret = 0;
 
  send_ack:
@@ -501,7 +501,7 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request,
     /* Circuit has been closed on failure of transmission. */
     goto done;
   }
-  if (status != HS_INTRO_ACK_STATUS_SUCCESS) {
+  if (status != TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS) {
     /* We just sent a NACK that is a non success status code so close the
      * circuit because it's not useful to keep it open. Remember, a client can
      * only send one INTRODUCE1 cell on a circuit. */

src/or/hs_intropoint.h

@@ -19,13 +19,6 @@ typedef enum {
   HS_INTRO_AUTH_KEY_TYPE_ED25519 = 0x02,
 } hs_intro_auth_key_type_t;
 
-/* INTRODUCE_ACK status code. */
-typedef enum {
-  HS_INTRO_ACK_STATUS_SUCCESS    = 0x0000,
-  HS_INTRO_ACK_STATUS_UNKNOWN_ID = 0x0001,
-  HS_INTRO_ACK_STATUS_BAD_FORMAT = 0x0002,
-} hs_intro_ack_status_t;
-
 /* Object containing introduction point common data between the service and
  * the client side. */
 typedef struct hs_intropoint_t {

src/trunnel/hs/cell_introduce1.c

@@ -519,6 +519,7 @@ trn_cell_introduce_ack_new(void)
   trn_cell_introduce_ack_t *val = trunnel_calloc(1, sizeof(trn_cell_introduce_ack_t));
   if (NULL == val)
     return NULL;
+  val->status = TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT;
   return val;
 }
 
@@ -550,7 +551,7 @@ trn_cell_introduce_ack_get_status(const trn_cell_introduce_ack_t *inp)
 int
 trn_cell_introduce_ack_set_status(trn_cell_introduce_ack_t *inp, uint16_t val)
 {
-  if (! ((val == 0 || val == 1 || val == 2))) {
+  if (! ((val == TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT || val == TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS || val == TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID))) {
      TRUNNEL_SET_ERROR_CODE(inp);
      return -1;
   }
@@ -587,7 +588,7 @@ trn_cell_introduce_ack_check(const trn_cell_introduce_ack_t *obj)
     return "Object was NULL";
   if (obj->trunnel_error_code_)
     return "A set function failed on this object";
-  if (! (obj->status == 0 || obj->status == 1 || obj->status == 2))
+  if (! (obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT || obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS || obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID))
     return "Integer out of bounds";
   {
     const char *msg;
@@ -606,7 +607,7 @@ trn_cell_introduce_ack_encoded_len(const trn_cell_introduce_ack_t *obj)
      return -1;
 
 
-  /* Length of u16 status IN [0, 1, 2] */
+  /* Length of u16 status IN [TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT, TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS, TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID] */
   result += 2;
 
   /* Length of struct trn_cell_extension extensions */
@@ -638,7 +639,7 @@ trn_cell_introduce_ack_encode(uint8_t *output, const size_t avail, const trn_cel
   trunnel_assert(encoded_len >= 0);
 #endif
 
-  /* Encode u16 status IN [0, 1, 2] */
+  /* Encode u16 status IN [TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT, TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS, TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID] */
   trunnel_assert(written <= avail);
   if (avail - written < 2)
     goto truncated;
@@ -687,11 +688,11 @@ trn_cell_introduce_ack_parse_into(trn_cell_introduce_ack_t *obj, const uint8_t *
   ssize_t result = 0;
   (void)result;
 
-  /* Parse u16 status IN [0, 1, 2] */
+  /* Parse u16 status IN [TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT, TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS, TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID] */
   CHECK_REMAINING(2, truncated);
   obj->status = trunnel_ntohs(trunnel_get_uint16(ptr));
   remaining -= 2; ptr += 2;
-  if (! (obj->status == 0 || obj->status == 1 || obj->status == 2))
+  if (! (obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT || obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS || obj->status == TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID))
     goto fail;
 
   /* Parse struct trn_cell_extension extensions */

src/trunnel/hs/cell_introduce1.h

@@ -12,6 +12,9 @@ struct trn_cell_extension_st;
 struct link_specifier_st;
 #define TRUNNEL_SHA1_LEN 20
 #define TRUNNEL_REND_COOKIE_LEN 20
+#define TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS 0
+#define TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID 1
+#define TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT 2
 #if !defined(TRUNNEL_OPAQUE) && !defined(TRUNNEL_OPAQUE_TRN_CELL_INTRODUCE1)
 struct trn_cell_introduce1_st {
   uint8_t legacy_key_id[TRUNNEL_SHA1_LEN];

src/trunnel/hs/cell_introduce1.trunnel

@@ -12,6 +12,11 @@ extern struct link_specifier;
 const TRUNNEL_SHA1_LEN = 20;
 const TRUNNEL_REND_COOKIE_LEN = 20;
 
+/* Introduce ACK status code. */
+const TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS    = 0x0000;
+const TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID = 0x0001;
+const TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT = 0x0002;
+
 /* INTRODUCE1 payload. See details in section 3.2.1. */
 struct trn_cell_introduce1 {
   /* Always zeroed. MUST be checked explicitly by the caller. */
@@ -32,7 +37,9 @@ struct trn_cell_introduce1 {
 /* INTRODUCE_ACK payload. See details in section 3.2.2. */
 struct trn_cell_introduce_ack {
   /* Status of introduction. */
-  u16 status IN [0x0000, 0x0001, 0x0002];
+  u16 status IN [TRUNNEL_HS_INTRO_ACK_STATUS_SUCCESS,
+                 TRUNNEL_HS_INTRO_ACK_STATUS_UNKNOWN_ID,
+                 TRUNNEL_HS_INTRO_ACK_STATUS_BAD_FORMAT];
 
   /* Extension(s). Reserved fields. */
   struct trn_cell_extension extensions;